The growing capabilities and the impressive skill of their operators elevate the threat from Iran’s unmanned air vehicles (UAVs) from a nuisance to a strategic level on par with Iran’s missiles and rockets threat on Israel.
Iran has been developing and expanding its Unmanned Air Vehicles fleets ever since the 1980s. They now comprise a wide spectrum of types that range in size and function from aircraft size, high flying reconnaissance UAVs to small, low-cost “suicide” ones. Until fairly recently, Israel’s military regarded the threat from Iran’s UAVs – either operated by Iran’s armed forces or by their proxies in the region – as a minor component of the overall military threat, compared to the major strategic threat from Iran’s fleet of ballistic missiles and its proxies’ rockets deployed in Iraq, Syria, Lebanon, Yemen, and Gaza.
This view seems to have changed dramatically, judging by recent reports in the Israeli and US media and strong statements made by Israel’s leadership. Amos Harel, Haaretz daily military analyst, reported that “Iran relies on UAVs as a counterweight to Israel’s air superiority”, adding that ” Israel’s military High Command is worried by the spread of Iran’s UAV capabilities to more and more of Iran’s proxies.”
Three months later, the same concern was expressed by top Israeli leaders. In his September 12, 2021 speech to the Reichman University’s Institute for Counter-Terrorism, Israel’s Minister of Defense Benny Gantz disclosed that “One of Iran’s most potent weapons is its fleet of UAVs.” According to Gantz, “This is an array of lethal and precise weapons, that like ballistic missiles can traverse thousands of kilometers. The Iranians produce and provide these air vehicles to their proxies, who in turn use them in coordination with and under the command of the Revolutionary Guard and its Quds Brigades.” Gantz, in fact, thereby elevated Iran’s UAVs to the top rank of threats, on par with Iran’s nuclear threat.
Israel’s Prime Minister Naftali Bennett was even blunter. In his September 27, 2021 speech to the UN General Assembly, he emphatically stated that “Iran has recently established a new terror weapon unit…. swarms of armed UAVs carrying lethal weapons that can strike anywhere, anytime.” Moreover, he warned that “Iran has already used these lethal UAVs, dubbed ” Shahed 136″ to attack Saudi Arabia, US bases in Iraq and cargo ships on the open seas.” He warned that “Iran intends to arm its proxies in Yemen, Iraq, Syria, and Lebanon with hundred – and later with thousands – of this kind of UAVs.” Remarkably, Bennett made no mention of the Iranian missile threat. Taken together, Bennet’s and Gantz’s statements testify to the mounting concern in Israel over the threat of Iran’s UAVs, a threat that by itself is not new but which has now reached a kind of “critical mass” that render it equivalent to the nuclear threat and that overshadows the missile and rocket threats from Iran and its proxies.
Apparently, Iran’s UAVs have evolved into an issue of concern for the US administration too. A recent Wall Street Journal article, titled “Iran Armed Drone Prowess Reshapes Security in the Middle East” discloses that “Teheran uses off the shelf materials to manufacture armed drones that challenge the US and its allies in the region.” The article proceeds to quote unnamed sources in Europe, the United States, and Israel who say that Iran’s fast-expanding capabilities to design, manufacture and deploy UAVs “Are altering the balance of power in the region.”
Following the October 10, 2021 attack by Iranian-made UAVs on US troops in the El Tanf base in Syria, the administration sanctioned Iranian persons and industries engaged in UAV design and manufacturing. It seems, then, that US and Israel share similar views about this new threat.
Iran’s engagement in developing, deploying, and transferring UAVs to its proxies is not a new phenomenon. Iranian UAVs operated by Hezbollah penetrated Israeli airspace already 16 years ago, even before the 2006 Lebanon War. In July 2006, while that war was still raging, Hezbollah launched three or four bomb-laden UAVs towards central Israel. One suffered a technical failure and crashed near the Lebanese border, while two more were shot down by air-to-air missiles fired from Israeli F-16 fighter jets. The fate of the fourth one – if there was a fourth – is not known. Following the 2006 war, Hezbollah’s Iranian-supplied UAVs made several attempts to reconnoiter Israel, all being intercepted and shot down. In addition, Iran itself tried to send its own UAVs into Israel’s airspace at least twice, once in February 2018 from an Iranian-operated airbase in Syria and again in May 2021 from Iraq. On both occasions, the UAVs were destroyed before penetrating Israeli airspace.
Since almost a decade ago, Iran’s proxies in Gaza have been stoking up with locally made – but Iranian designed – armed UAVs. As early as 2012, during Operation Pillar of Defense, the Israel Defense Forces (IDF) destroyed a Hamas UAV poised to take off from the old Gaza airport runway. During the July – August 2014 escalation (operation Protective Edge), Hamas launched several UAVs into Israel, which managed to cross the Gaza border. Two or three of them were shot down by Patriot air defense systems.
In the recent May 2021 escalation (Operation Guardian of the Walls), Hamas unveiled a new type of suicide UAV – unseen before in Gaza, but familiar from Iran’s proxies operations in Yemen and Lebanon. Hamas launched five or six of them towards Israeli border towns. Most, if not all were shot down by the Iron Dome short-range air and missile defense system. Hamas claimed that one of its new UAVs managed to break through Israel’s defenses, hitting a “chemical plant” within Israel. A video clip released by Hamas shows a UAV diving and exploding near the Nirlat paint factory in Kibbutz Nir Oz, about 3 km (1.9 miles) from the Gaza perimeter.
The proficiency of Iran’s UAVs and their operators have been demonstrated repeatedly in the region ever since the onset of the war in Yemen in 2014. Iran’s UAVs operate in the skies of Saudi Arabia, the Persian Gulf, Iraq, and Syria. They have been extensively used in a broad spectrum of operations, including retaliation against ISIS bases, battlefield support of the Assad regime forces in their campaign to regain control in Syria, in attacking cities, national infrastructures, and oil targets in Saudi Arabia, and in targeted killing of high-ranking officers and officials of the internationally recognized Yemeni government.
Scant attention was paid to the role of Iranian originated, Quds brigade smuggled UAVs in the fighting inside Yemen and the war of attrition against Saudi Arabia. However, this changed abruptly after the surprise attack by Iran’s UAVs on September 14, 2019, against two of Aramco’s main oil facilities in Saudi Arabia. In a meticulously planned operation that surprised most if not all Intelligence services in the West (Including Israel’s Mossad), less than 30 low-cost Iranian UAVs caused tremendous damage to two of Saudi Arabia’s key oil installations, reducing oil exports capacity by more than one-half for several months. This brilliantly conceived operation, a veritable “mini-Pearl Harbor” used mainly of the Shahed 136 suicide UAVs later mentioned by Israel’s PM’s UN speech. The Iranian UAV swarms reached their targets in the depth of Saudi Arabia’s hinterland with complete surprise, remaining undetected by Saudi Air defenses. Hence, no attempt was made to intercept them. Their precision in hitting their targets was exceptional.
In July 2021 Iran’s UAVs starred once again in the world media when for the first time in ever a suicide UAV managed to hit and cause casualties a moving commercial ship at sea. The oil tanker MT “Mercer Street” sailed from Dar-el-Salaam, Tanzania to the UAE oil terminal of Fujairah when it was attacked on July 28 and then again on July 29 by unmarked UAVs. While the first attack or attacks on July 28 failed, the next day was they were successful. The diving UAV achieved a bull’s eye on the ship’s bridge, killing the British captain and his Romanian bodyguard.
The stricken ship was escorted by warships of the US Navy Fifth Fleet and continued on its voyage to Fujairah. Upon arrival, the US Central Command (CENTCOM) conducted a thorough investigation and released some of its results to the public. One of the key findings was that the debris of the attacking UAV was identical to that of the Iranian Shahed 136 UAVs that had devastated the Saudi oil installation in Abqaiq two years earlier. This proved the Iranian connection to the attack on a civilian ship on the high seas. As a result, Israel, the US, the UK, and Romania named Iran the perpetrator of this outrage. The international media defined it as an act of terror.
The Japanese-owned, Liberian- flagged MT Mercer Street is operated by “Zodiac Maritime”, a London-based company owned by the Israeli tycoon Eyal Ofer. The Israeli connection brought forth a theory that the Iranian action against this ship was part of a broader covert war between the two countries. One source in the Iranian media claimed that the attack was in retaliation for unspecified Israeli attacks on Iranian installations in Syria. Iran’s government, however, washed its hands from the whole affair. As in the case of the attack on the Saudi oil installations in 2019, no smoking gun could conclusively prove Iran’s guilt, since the UAV launch point remained unknown.
At the time of the attack, Mercer Street was sailing close to the Omani coastline about 480 km (298 miles) away from the nearest Iranian coast. Its distance from the Omidiyeh Iranian Air Force Base for which the September 2019 UAV attack on Saudi oil installation originated, was about 1500 Km (932 miles) – about twice as far as the distance traveled by the Iranian UAVs during the September 2019 oil attack. One Western source hypothesized that the attack on the Mercer Street originated in Houthi-held Yemen, but this is highly doubtful. The distance between Houthi-held territory and the point where Mercer Street was struck is about 1700 km (1056 miles). It would be more reasonable to the Houthis to strike at the ship when it was closest to the Yemeni coast in its voyage from Dar-el- Salam to Fujairah, which is about 1300 km (808 miles) from Sana’a, rather than attacking it when it was almost beyond reach nearing the Strait of Hormuz.
It is therefore more reasonable to assume that the attack originated in Iran. In November, Minister of Defense Gantz identified the location of two Iranian UAV bases at Chabahar and the Island of Queshm that he said were being used for sea control. Chabahar and the Queshm Island bases are located 410 km (255 miles) and 670 km (416 miles) respectively from the attack site on Mercer Street. If indeed these were the launch points for the attack on Mercer Street, it would allow the same Shahed 136 that had been used against the Saudi oil installation to be used against Mercer Street too. Nevertheless, Israeli media sources reported that the range of the Shahed 136 was indeed doubled to 1500 km (932 miles). With such a range capability, the Shahed 136 could attack Israel directly from Iran –which is about 1200 km (746 miles) away from Israel at its closest point. Perhaps this was Gantz’s mind when he warned about lethal Iranian UAVs “that could traverse thousands of kilometers.”
While the number of UAVs that attacked Mercer Street – two or three – was much smaller than the swarms that assaulted the Saudi oil installations two years earlier, the later operation was almost as impressive technically and operationally. The Iranian perpetrators had no difficulty identifying the target ship from the general sea traffic in the busy sea lanes. This is because ships at sea must constantly broadcast their locations. At the same time, the ability to intercept and strike it with precision while in motion was far from a trivial achievement. This required some feats of navigation and the ability to home on a moving target, either by onboard sensors or by remote pointing from another air or sea vessel. In contrast to the attack on the Saudi oil installations, the Mercer Street attack took place in broad daylight. It stands to reason that a daylight operation was mandatory to correctly identify the target ship and avoid erroneously attacking an uninvolved ship. This in turn could indicate that the Iranian operators maintained real-time data and visual links with the attacking UAV, hundreds of kilometers from the launch point – a capability hitherto the domain of the more industrialized countries.
Possibly, the attack on Mercer Street was part of a broader operation that was ultimately aborted. Five days later, a group of armed persons boarded and took control of the Asphalt Princess, another oil tanker on its way to Fujairah, but which had no connection with Israel. The armed persons – who conversed among themselves in Persian- instructed the captain to sail towards the Iranian coast. About one hour later, without any explanation, the group debarked the ship and let it resume its original course. It could be significant that the two ships – Mercer Street and Asphalt Princess – had some similarities and almost identical painting schemes. During the incident, some neighboring ships reported interrupted communication. The Iranians denied any connection to the aborted hijacking of the Asphalt Princess, other than offering to send help.
Did the Iranians plan to highjack Mercer Street? There is no evidence of this. Yet it is not unreasonable to speculate that the UAV attack on Mercer Street was part of a larger plan that was aborted, perhaps due to the death of uninvolved nationals of countries who maintain cordial relations with Iran. Moreover, the abduction of the ship after those killings could have caused diplomatic complications that Iran was anxious to avoid, hence the rest of the operation – if such existed – was aborted.
Mercer Street was not the first Israeli- linked ship to be attacked in that region. On February 26, 2021, the MV Helios Ray, an Israeli- owned car transporter, was attacked in the Gulf of Oman while sailing from Dubai to Fujairah. The damage forced the ship to return to the port of origin for repairs. Less than one month later, on March 25, 2021, the MT Lorry, an Israeli-owned container ship, was attacked in the Arab Sea while sailing to Gujarat harbor in India. There were no casualties, the damage was light, and the ship continued its voyage. Three weeks later, on April 3, 2021, the MT Hyperion Ray, another Israeli- owned car transporter was attacked while sailing in the Gulf of Oman towards Fujairah. In this case, too, there were no casualties and the damage was light.
Thus, the July attack on Mercer Street was the fourth consecutive attack on vessels associated with Israel. The first attack on the Helios Ray was carried out by attaching small explosive charges to the ship’s side above the waterline – a method used previously by Iran’s navy to attack oil shipping several years ago. The latter attacks, however, were done differently. Initial reports of the second and third attacks cited “missile attacks”, but later it was reported that at least one of them was executed by a UAV. It seems that the Mercer Street incident was the third Iranian UAV attack on Israeli-linked shipping in the seas near Iran, and the first one was successful, albeit on the second attempt.
It can be assumed that the Iranian planners intended to cause enough damage to draw media attention and force the attacked ships to seek shelter for repairs, but not to cause the death of uninvolved civilians. In this assumption, the killing aboard the Mercer Street was undesirable collateral damage.
Major Features of the UAV Threat
Apart from the above-described land and sea operations, Iran’s UAVs are busy almost daily in attacking Saudi targets in the southern and central region of the Kingdom They are also active against US forces in Iraq and Syria (Nine attacks at the time of writing and counting) and in a sporadic incursion into Israeli airspace. The improving performance of Iran’s UAVs as well as the burgeoning expertise of their Iranian controllers is turning them into a significant strategic threat to Israel. This threat is fast becoming no less severe than that from the rockets and missiles of Iran and its proxies.
In his September address to the UN, Israel’s Prime Minister Bennett cited the attacks on Israeli shipping as a confirmation of the decisiveness of the new UAV threat and was quite explicit about its nature: Swarms of hundreds, if not thousands of Iranian supplied UAVs to its proxies in Yemen, Iraq, Syria, and Lebanon, could be used for attacking Israel. To evaluate the significance of this threat we need to assess the growing importance of UAVs in Iran’s military force structure – but to do this, it first needs to define “what is a UAV?”
Manned aircraft come in an extraordinary variety of forms and functions: From single-seat, single motor, propeller-driven private Cessnas to Boeing jumbo jets carrying hundreds of passengers across the world’s oceans and to the giant nuclear bombers such as the US B-52. Likewise, UAVs come in an almost infinite variety of forms, functions, and purposes. Strictly speaking, any flying object that can fly stably to any distance – even a short one – but without a human pilot on board, is a UAV. This includes balsa wood, rubber band powered model aircraft, quadcopters purchased in toy shops as well as giant remotely piloted aircraft like the US Global Hawk that can fly non-stop from the US to the Middle East, one example of which was shot down by an Iranian air defense missile in June 2019 over the Straights of Hormuz. The term “UAV” has become even more ambiguous with the appearance of the so-called “Cruise Missile” which is essentially nothing but a UAV that is powered by a Jet engine. Iran, for example, has at least two types of jet-driven UAVs, which are designated by the media (as well as by some analysts) as “cruise missiles.” This paper will apply the term “UAV” to all militarily significant unmanned aircraft, whether propeller or jet-driven. Quadcopters and multi-copters of any kind- sometimes called “drones” – are a class of their own and will not be included in the following discussion.
As in Israel and the US, Iran’s early generation UAVs were designed for use as reconnaissance aircraft to obtain real-time battlefield intelligence. They carried video cameras and transmitted back still photos and video footage about enemy positions, deployment, and movements. Later, they had air-to-ground weapons fitted under their wings, enabling them to strike the targets identified through their optical sensors. Once the art of navigation by satellites was perfected and with GPS and GLONASS satellite navigation systems coming online, the Iranian turned some of their simpler and cheaper reconnaissance UAVs into suicide UAVs that destroy targets by crashing into them, rather than by aiming air to ground munitions at them.
Suicide UAVs are favored by the Iranians since their simpler versions can be manufactured in the improvised workshops of their proxies all over the Middle East, including the Hamas and Islamic Jihad in Gaza. The Wall Street Journal article already cited above reveals that the Iranian purchase off-the-shelf commercial-grade components and materials for the production of UAVs both by themselves and by their proxies. Piston engines, for example, are purchased from China’s Ali Baba for $500 per piece, free of any export license since this small air motor has wide civilian use, including for powering model aircraft built by enthusiasts in the US and Europe. The servo motors used to move the control surfaces of their UAVs originate in the South Korean toy industry. One of the critical components of the Shahed 136 of the Saudi oil installation FAME was made in Sweden and is used in the food industry. Software for guidance and control – created by Western enthusiasts – can be freely downloaded from ArduPilot, a site that offers such software for remotely controlled air and ground vehicles.
The manufacturing of such rudimentary yet effective suicide UAVs could be simpler than the production of precision rockets, hence the growing use of UAVs in regional wars. In Yemen, the Houthi insurgents initially used unguided rockets to harass Saudi Arabia’s southern cities but have later shifted to suicide UAVs since the Saudi ground-based defense systems have more difficulty intercepting them – but perhaps also because such UAVs are easier to mass-produce in the workshops of Houthiland. Following the 2020 six weeks war of Nagorno Karabakh where Azeri attack and suicide UAVs devastated the Armenian armed forces, Iran held a giant arms exposition where it showed off and flew UAVs of all three varieties: Reconnaissance, ground attack, and suicide attack. As the unnamed Iranian official said to the Wall Street Journal: “Developing a nuclear weapon would take years. With drones, just a few months. Drones have changed the balance of power in the Middle East.”
The main drawback of combat UAVs – whether releasing air to ground weapons or crashing into the target – is the relatively small weight of explosives carried aboard. Heavy Iranian rockets like the Zelzal or its precision sibling the Fatah 110 carry warheads of more than half a ton of explosives. The Shahed 136s that hit the Saudi Oil installation and the Mercer Street carried about 20 kg (44 lbs) of explosives. At the same time, all suicide UAVs are precision weapons with pinpoint accuracy. Therefore, the cumulative damage from a large number of even small warheads can be decisive, as shown in the case of the Saudi oil installation.
UAVs have an advantage over rockets and ballistic missiles because of the unpredictability of their flight path. A rocket or ballistic missile travels along a direct line between the launch point and the target. Hence, since the prospective launch zone of Hezbollah rockets from Lebanon and Hamas rockets from Gaza are well known, Israel’s defense system can deploy in the directing of the incoming threats. In contrast, UAVs can follow any route selected by their operators, and with sufficient fuel in their tanks can approach their targets in roundabout routes. For example, a Hamas UAV taking off from Gaza could theoretically approach Tel Aviv from the north. Hence, detection of and defense against UAVs must be circumferential – 360º – rather than focusing on one specific direction. The 360 degrees exposure dilutes the defense’s assets. Moreover, most UAVs have small dimensions, and many are made from low signature composite materials – presenting reduced radar signatures. Their small piston engine has a tiny heat signature, hard to detect by thermal sensors. Flying low and slow, they prove hard to detect by radars tuned to provide early warning against fast, high flying manned aircraft – as may have happened in the recent Nagorno Karabakh war.
UAVs are not launched in salvoes but rather take off and fly individually. When arriving separately at the target area, they can be picked off one by one. To overcome this vulnerability, operators developed “Swarming” techniques by which bunches of UAVs fly in a coordinated manner and can, for example, synchronize their arrival at the target area – each arriving from its own unique direction – saturating the defenses both temporally and directionally. This technique was already employed by the Iranians in the September 2019 attack on the Saudi oil installations, where all the attacking UAVs were probably synchronized to arrive at their target within a concise time window. The Iranians demonstrated this capability in a recent military exercise (“Great Prophet 15”) in January 2021, which featured a swarm of 4 Shahed 136s simultaneously diving and crashing into various ground targets with remarkable precision. Thus, as PM Bennett noted, the most ominous feature of the UAV threat on Israel is from mass raids by synchronized swarms of hundreds if not thousands of UAVs.
Tipping the Balance of Power in the Middle East?
The success of Iran’s UAVs in Saudi Arabia and the Azeri ones in the Nagorno Karabakh war shows that Israel must assume that in any war situation, Iran’s proxies in Syria, Lebanon, and Gaza will deploy armed and suicide UAVs that could precisely strike and take out key targets within Israel’s homeland, such as military reserve storage depots and force concentrations. Moreover, the UAVs of Iran’s proxies will have the capability to hit armor and supply vehicles in motion, thereby disrupting maneuvering forces. Above all, they are likely to target Israel ground-based air defenses as their first priority. The accumulated damage to Israel’s warfighting capability from swarms of hundreds of precise UAVs might equal if not surpass that from salvoes of rockets and missiles.
The strategic significance of the growing UAV threat seems to be debated within Israel’s defense establishment. According to an unnamed military source quoted in Harel’s article, the Iranian UAVs “are not game-changers. UAVs can harass, gather intelligence and deter, but cannot achieve victory.” The Armenians, soundly defeated by Azerbaijan’s fleets of ultra-modern UAVs would have agreed with the quoted opinion of the unnamed Israeli officer. Decades ago, the IDF made the same mistake of underestimating the significance of an earlier threat, when it determined that “missiles and rockets don’t win wars” and tried to block the development of anti-missile defenses. It seems that the political leadership of the country does not share the optimistic assessment of the quoted Israeli officer, expressing their concerns in high-level international forums. In fact, Prime Minister Bennet dedicated as much time to the UAV threat as to the Iranian nuclear threat in his recent UN speech thereby indicating that he does not see Iran’s UAVs as secondary weapons of “Harassment, intelligence gathering, and deterrence” but as a viable strategic threat. It may well be that the Israel Defense Forces have in the meantime rethought its position as indicated by recent media reports. An article on the international air exercise held on October 2021 in Israel, stated that “Israel’s Air Force is closely tracking two issues of concern: the deployment of Iranian ground-based air defenses in Syria, and their enhanced use of UAVs.”
A recent article in an Israeli daily disclosed that Israel has been acting in the last few months to mobilize the international community to combat the spread of Iran’s UAVs, assigning it equal weight to Iran’s nuclearization in the struggle against Iran’s quest for hegemony in the Middle East. Judging by these reports it seems that the top Israeli leadership does perceive Iran’s UAVs as a veritable game-changer.
The Challenge of UAV Defense
Roughly speaking, combat UAVs come in two classes: The first one includes medium to large UAVs flying at medium altitudes, used for reconnaissance and for attacking ground targets with precisely guided air to ground missiles or glide bombs. UAVs of this class operate individually rather than in swarms and are designed to return to base after completing their missions – in other words, they are multi-use systems designed for repeated operations. The challenge of defending against them is rather similar to that of defending against manned aircraft, except that UAVs generally fly at lower speeds.
The second class includes single-use suicide or “kamikaze” UAVs. Generally speaking, they tend to be smaller and less sophisticated than Class 1 UAVs. They fly at low to very low, ground-hugging altitudes, and can operate in swarms. From the aspect of the defender, their threat is more akin to precision rocket salvoes.
The UAVs launched against Israel to date by Hezbollah, Hamas and the Iranians themselves were mainly (but not exclusively) of the first class and were intercepted and shot down by Israel’s air force. Initially, hostile UAVs were shot down by air-to-air missiles fired from fighter aircraft. On one occasion, an Iranian UAV arriving from Syria was shot down by gunfire from an Apache helicopter. Later, during the 2014 operation Protective Edge and the 2021 operation Guardian of the Walls, Hamas UAVs were shot down by ground-based air and missile defenses – “Patriot” and “Iron Dome” respectively.
UAVs of both classes are not immune to air defenses, whether ground-based or airborne. If anything, the opposite is true: It is relatively easy to shoot down a slow-flying UAV, provided that it is detected in time and provided that the defender uses the appropriate weapons against small and stealthy targets. The challenge is timely detection and tracking and in the case of UAV swarms – avoiding being overwhelmed. Moreover, UAVs are precision weapons, hence it is not enough to kill some of them or even many of them: The operational requirement is to kill them all – in the language of missile defense, to achieve a zero or near zero leakage rate. Defending against swarms of UAVs arriving simultaneously from every direction at treetop levels is a formidable challenge to any air defense system, a challenge that may well require the development and fielding of new technologies and operational doctrines.
UAVs in Adjacent Arenas
“UAV Wars” where air defenses were pitted against ground attack UAV have gone on in northwest Syria, in Libya, in the South Caucasus, in Saudi Arabia, in Yemen, and most recently – in Ethiopia. In the Second Nagorno Karabakh War of October–November 2020, Azerbaijan threw into the battle its newly purchased fleet of ultra-modern class 1 and class 2 UAVs, practically obliterating the Armenian’s Soviet-era ground-based air defense systems. Losing the capacity to defend the airspace paved the way to a crushing Armenian defeat. In the still-ongoing civil war in Libya, Turkish class 1 UAVs deployed in support of the internationally recognized government in Tripoli, demolished the ground-based air defenses of the rival government of Benghazi, proceeded to wreak havoc on the Benghazi ground forces thereby allowing the Tripoli government to break the siege on its capital city and regain control of large tracks of the country. During the 7 days long “Operation Spring Shield” in February – March 2020, Turkish Class 1 UAVs demolished the opposing Syrian air defenses, then proceeded to destroy Syrian tanks, troop concentrations, and command posts. Recent reports from the ongoing civil war in Ethiopia are painting a similar picture. The Ethiopian government, on the verge of defeat by the Tigray rebels, has recently turned the table with the aid of Class 1 UAVs of Chinese, Turkish and Iranian origins.
The situation in Saudi Arabia is more complex. Since 2015 the Houthis in northern Yemen have been conducting a war of attrition against the Kingdom, using rockets, ballistic missiles, and UAVs –mainly of class 2 – to harass population centers, military installations, economic value targets, and state symbols across the length and breadth of Saudi Arabia. In the south, close to the Yemeni border, the targets are mainly towns, airports, and oil facilities. In the Kingdom’s deeper hinterland, the Houthis target state symbols (e.g., royal palaces) and oil industry infrastructure, such as pumping stations serving oil pipelines. The Iranians surreptitiously intervene in this harassment campaign, by launching “Houthi looking” UAVs from their territory into Saudi Arabia. The Saudi extensive air defenses are vigorously battling the incoming UAVs using ground-based defenses (Patriot) and airborne defenses combining early warning aircraft with manned interceptor fighter aircraft. The information offered by the media on the evolution of the air campaign in Saudi Arabia is at best sketchy, providing an incoherent picture of the situation due to the heavy use both sides make of verbal and photographic data for propaganda purposes. All the same, some general conclusions can be gained even from the incomplete and biased information published hitherto.
One conclusion is that Saudi Arabia encounters some difficulties defending its hinterland against Class 2 UAVs, especially when they arrive from unexpected directions. The most outstanding example was the failure to detect and engage the Class 2 UAVs coming from Iran’s direction that struck the oil installations in September 2019. This however was not the only case. In February 2021, for example, three suicide UAVs launched from Iraqi territory struck a royal palace in Riyadh, the capital city. It seems that in both cases Saudi Arabia air defenses failed to detect the incoming UAVs and were powerless to intercept them.
Another conclusion is in the southwestern regions of the kingdom. Its air defenses enjoy some success against the Houthi UAVs (according to Saudi and US sources – an outstanding success). From the photographic evidence released by the Saudi military, it seems that they use both ground-based defense using Patriot batteries and airborne defense, using Saab 2000 early warning aircraft and air-to-air armed F -15 fighter jets. The Saudis sometimes claim the destruction of dozens of Houthi UAVs in a single day and release convincing-looking video footage on the media. Nevertheless, there is no doubt that some UAVs manage to penetrate through the defensive shield. For example, the Abha International Airport, about 150 km (93 miles) away from the closest Yemeni border, sustained casualties and damages from Houthi UAVs during the summer and fall months of 2021 (The Saudis claim that the UAVs were intercepted and that the casualties and damages were inflicted by the falling debris). This highlights the requirement from the defense to achieve an extremely high success rate against the incoming UAVs, since the damage from the “leakers” that get through overshadows the success in preventing damage from the destroyed UAVs that don’t get through.
Saudi Arabia, whose huge territory is almost the size of Western Europe, lacks a nationwide early warning system against low and slow UAVs. This leaves Its borders practically open to incursion by low or medium-altitude aircraft. Its ground-based air defenses, consisting mainly of the older generation Patriot 2 and the newer Patriot 3, are optimized for intercepting high flying combat aircraft and ballistic missiles rather than low flying UAVs. The prospects of the Kingdom buying “Iron Dome” systems (initially optimized against rockets, and only recently upgraded for UAV interception) are practically nil, but it may yet emulate the Emirates by purchasing the newly developed South Korean M-SAM II, a joint development with Russia’s defense industry. Acquiring and fielding those systems may take years. Saudi Arabia’s nascent military industry announced in 2020 that it is developing an anti-UAV system. Still, from the published details it seems that the new system will offer only localized defense against quadcopters (“drones”) rather than horizontal flight UAVs of both categories. It seems that Saudi Arabia has no immediate military option to seal its skies against the incursion of hostile UAVs from Yemen, Iran, or Iraq. Perhaps this is what compelled the Kingdom to seek a diplomatic solution and to open negotiations with Iran. It is perhaps not too far-fetched to conclude that the simple, unsophisticated UAVs originating in Iran managed to humble the powerful Royal Saudi Air Force, gaining for Iran a significant strategic achievement. The statement of the unnamed Iranian official quoted above that the UAVs are tipping the military balance in the Middle East was not far off the mark.
Meanwhile, in another corner of the Middle East UAV’s have been battling Russian air defenses in Syria. When Russia acquiesced to Bashar Assad’s entreaties to save his regime against the then victorious insurgents, the latter granted Moscow an airbase in Khmeimim and a naval base in Tartus, both in the northwestern corner of Syria. As soon as the Russian intervention commenced, those two bases – but mostly the airbase – came under frequent insurgent attacks, initially from mortars and later from UAVs. On December 31, 2017, the Khmeimim airbase suffered a major insurgent strike, initially thought to come from mortars but later confirmed as coming from UAVs. The attack caused the death of two Russian persons and damaged several aircraft. Unofficial sources claimed that eight aircraft were hit, two of which were total losses. One week later, on the night between January 5 and 6, 2018, 13 insurgent UAVs attacked both Russian bases (Ten UAVs attacked Khmeimim and three attacked Tartus). It seems that this time the Russians were ready. According to their statements, the attack was completely foiled, with seven UAVs being downed by ground-based air defenses and the rest forced to land by a Russian cyber operation. The photographic evidence released by the Russians shows two types of UAVs: One is a Chinese-made, hand-launched UAV sold to all buyers through Ali Baba under the name “Skywalker.” The other was a rather largish, rudimentary balsa wood radio-controlled model aircraft of unknown provenance carrying tiny bombs under its wings and probably built by the Insurgents themselves. The UAV attacks on the Russian bases are still going on sporadically. For example, in July 2021 the Russian reported downing 13 hostile UAVs, and a month later, in August, they reported the downing of a formidable number – 45 in all. Russia claims a 100% success rate and no losses or damages in the ongoing battle against the insurgents’ UAVs.
The Russian military is largely silent about its doctrine and weapons for combating UAVs, but non-Russian sources report that it consists of three major components: First, the Russians re-tuned their radars to detect the small size, low and slow air vehicles. Second, they set up systems to interfere with navigation satellite communication (GPS and perhaps Russia’s own GLONASS), and third, they use Electronic Warfare (EW) to disrupt communication between the UAVs and their operators. It is also possible that the Russians are using cyber warfare to highjack control of incoming UAVs and land them safely away from their targets. The ground-based air defenses of the Russian enclaves are based largely on the SA -22 Pantsir which is equipped with two 30mm rapid-firing anti-aircraft guns – a legacy of WWII – and twelve small, short-range, heat-seeking ground to air missiles. While Pantsirs operated by Syrian and Libyan forces have been overwhelmed by modern Turkish UAVs, it seems that in the case of the Russian bases in Syria, the Pantsir remains effective against the rudimentary UAVs launched from the last anti- Assad enclave in North-Western Syria.
Comparing the UAV defense of Saudi Arabia and the arguably more effective Russian defense, four parameters stand out: the size of the defended area, the suitability of the defensive weapons to the mission of killing UAVs, the role of electronic and cyber warfare, and the sophistication of the aggressor’s air vehicles and operators. Territorial size seems to be decisive: The immense territory of Saudi Arabia and its extremely long borders make it difficult to erect a hermetic early warning fence against low flyers and practically allow an almost free ingress of UAVs into its territory. In contrast, the two Russian bases in Syria have the size of small towns, facilitating impermeable early warning fens around them.
As for weapons, Saudi Arabia relies on heavy manned fighter aircraft and Patriot air defense systems, both designed to engage high flying manned aircraft rather than low, slow and cheap UAVs. Using expensive Patriot interceptor missiles against fiberglass, propeller-driven model aircraft mass-produced in the workshops of Sana’a is tantamount to using a sledgehammer to kill gnats: Feasible but highly inefficient. The Russians, in contrast, are using lower-tech ground-based air defenses combining anti-aircraft guns with what is essentially shoulder-launched anti-aircraft missiles. The Russians are using electronic countermeasures (ECM) to disrupt the hostile UAVs and perhaps also cyber warfare (CW) to force them down. There is no information on the similar use of ECM of CW by the Saudis. Finally, the aggressor’s level of sophistication seems also to play a part. The Iranian have demonstrated high skill in inserting swarms of UAVs into Saudi Arabia’s hinterland, circumventing defensive systems, remaining unseen by early warning systems, and avoiding ground obstacles. The Syrian insurgents in the Idlib enclave that keep attacking the Russians with their simple UAVs lack the Iranian sophistication – so it stands to reason that their UAVs fly in straight lines along the shortest route – and hence the most predictable route – from the Idlib enclave to the Russian bases.
Elements of Effective Defenses Against Iran’s UAVs.
Today, the burgeoning UAV threat is an issue of concern not only in Israel but to the West at large. The Western defense industries are proposing a welter of new anti UAV weapons, some realistic and some bordering with science fiction. Of the cutting-edge weapons being developed, the closest to maturity is the high-power solid-state laser in which significant progress has recently been achieved both in Israel and abroad. A development program of 300 Kw mobile laser system has recently been initiated in the US. Since the level of power of the laser beam is directly proportional to its rate of kill, it may well be that such powerful lasers will be able to deal even with synchronized UAV swarms. Another cutting-edge technology being experimented with is Microwave beams, aimed to “fry” the electronics of incoming UAVs. One US company came up with the idea of reusable kinetic interceptors that kill the target UAV by metal-to-metal collision, without any explosives. The spent interceptor is then parachuted down for recycling. Other companies propose interceptor UAVs that shoot air-to-air missiles at the incoming hostiles or physically crash into them.
Class 1 UAVs that are generally used for reconnaissance and ground attack tend to be relatively large and heavy, necessitating takeoffs from and landings on suitable runways. Repeatedly damaging such runways by offensive actions could slow down Class 1 UAV operations. In contrast, the smaller types of Class 2 UAVs are launched from zero-length rails or catapults and are accelerated to take-off speed by small rockets or pressurized air bottles. Zero-length catapults of the types unveiled by Hamas during the May 2021 operation “Guardian of the Walls” can be assembled in a few minutes before the launch and disassembled immediately after it. Hence, they present temporary, quickly vanishing targets. Accordingly, the chances to hit them while deployed are slim, to say the least. As a result, the response to most Class 2 UAVs – i.e., the smaller types of suicide UAVs – will probably be defensive rather than offensive. In the case of Israel, the defensive brunt will befall on the shoulders of Israel’s Air Defense Command.
Unlike Saudi Arabia, Israel’s small territory facilitates the establishment of a seamless early warning perimeter around all its borders. Detection of low, slow, and small UAVs is the cornerstone of effective defense, without which no viable defense is feasible as we see in Saudi Arabia. Israel’s air defenses had already made significant steps in this direction when it upgraded the Iron Dome radars to detect small, low flying UAVs, proving its effectiveness during the 11-day long operation “Guardian of the Walls.”
The UAV threat does not replace the rocket and missile threat, but rather adds to it. Adding the mission of UAV defense to the already existing mission of rocket and missile defense could overwhelm the defense systems. It is therefore necessary to take quantitative measures to beef up the defensive shield. The number of defensive systems capable of dealing with both kinds of threats must be increased. Even then, synchronized UAV swarms coming from every direction could locally overwhelm the defense. Hence, the addition of new cutting-edge kill systems should be investigated, such as laser (already in development in Israel) and microwave systems. ECM systems might be able to destroy UAVs in masses. hence their integration in the defensive array should be pushed forward. Israel’s army has already employed ECM during the May 2021 operation “Guardian of the Walls”, but it seems they were of the local, short-range “Drone Dome” type made by Rafael, basically optimized against short-range quadcopters. Disrupting horizontal flying UAVs at long distances will probably require more powerful ECM systems, such as the Israel Aerospace Industry Elta Division “Scorpius” recently unveiled by the Israeli Ministry of Defense.
Finally, and most importantly: The cost per kill must be driven down. In combating rockets and missiles, the cost of defense has always been and remains higher than the cost of offense, giving the aggressor a financial advantage. This disparity becomes even more pronounced in the case of UAV when descending the technological ladder by the aggressor – i.e. switching from relatively expensive guided missiles and rockets into toy-like, fiberglass made small air vehicle powered and guided by amateur grade systems – forces the defender to climb up the technological ladder, from interceptor missiles to lasers and microwaves. Ultimately, it will be battlefield economics, as expressed by the cost per kill, that will determine who will have the upper hand: the aggressor or the defender.
Iran’s UAV can no longer be seen as secondary weapon systems that can merely “harass, gather intelligence and deter.” Rather, they have grown into a major weapon system that when applied properly can be a game-changer by themselves, as potent as the new generation of precision rockets and missiles of the Islamic Republic. The concerns voiced by Israel’s Prime Minister and Minister of Defense are justified and timely. It can only be hoped that Israel’s defense establishment will learn from the experience of others and will rapidly deploy the required offensive and defensive means to prevent Iran’s UAVs from tipping the military balance in the region.
 While the term “Drone” is widely used to denote all unmanned vehicles that rely on an aerodynamic lift for flying, it is also used to denote small rotary-wing flyers that are sold for entertainment and sed by the general public. To avoid ambiguity, this paper will use the technically correct term “Unmanned Air Vehicles (UAVs)” to denote all types of unmanned flyers, whether fixed or rotary wings.
 Harel, A., “Iran’s UAVs are a partial response to Israel’s air superiority,” Haaretz, July 16, 2021 (Hebrew) https://www.haaretz.co.il/news/politics/.premium.HIGHLIGHT-1.10004417
 Fouson. B. and Nissenbaum, D, “Iran Armed Drone Prowess Reshapes Security in the Middle East” Wall Street Journal, October 7, 2021, https://www.wsj.com/articles/irans-armed-drone-prowess-reshapes-security-in-middle-east-11633530266
 For a more detailed description and analysis of the September 2019 attack on Saudi Arabia oil installations, see Uzi Rubin, “Saudi Arabia’s Black September” https://jiss.org.il/he/rubin-saudi-arabias-black-september/
. Zaitun, Y., “Eurofighters and F 35s against Russian air defenses: report from the international air exercise in Israel,” Ynet, October 25, 2021 (Hebrew) https://www.ynet.co.il/news/article/ryugnr7iy
 Lis, Y., “Before the sanctions, Israel provided the US with information on the Iranian UAVs,” Haaretz, October 30, 2021 (Hebrew) https://www.haaretz.co.il/news/politics/.premium-1.10339681
 For a more detailed description and analysis of the UAV wars in Libya and Northern Syria, see Uzi Rubin, “UAVs in the skies of the Mediterranean.” https://jiss.org.il/en/rubin-uavs-in-the-skies-of-the-mediterranean/
 Payman, T., “Explosive-laden drones that targeted Saudi Arabia’s royal palace in the kingdom’s capital last month were launched by Iran-backed militia from inside Iraq” Mail Online, February 25, 2021 https://www.dailymail.co.uk/news/article-9300063/Drones-targeted-Saudi-royal-palace-launched-Iran-backed-militia-inside-Iraq.html
 This lesson was already learned from the V1 “Flying Bombs” campaign against Britain during WWII. The British, forewarned of the imminent attack by their excellent intelligence services, prepared a multi-layer defensive shield consisting of belts of anti-aircraft guns, integrated with squadrons of fighter aircraft (including the first British Jet fighters). In time, the defensive shield proved its capability and achieved a nearly 90% success rate. Yet, the few UAVs that did break through killed hundreds and caused extensive damage in London, forcing the allies to divert offensive resources from the land battles in France to ground and air assaults on the V1 launching sites.
 Helu, A., Saudi Arabia is developing a new counter-drone system, Defense News, January 1, 2020. https://www.defensenews.com/unmanned/2020/01/08/saudi-arabia-is-developing-a-new-counter-drone-system
 The similarity to the Improvised Explosive Devices (IED) comes to mind. IEDs – primitive mines consisting of lumps of explosives wrapped in rugs that are left in the open on roadsides have been taxing the best brains in the defense industries on how to detect and destroy them in time. High power lasers have been proposed for this task.