US and Israeli options
Although Iraq probably possesses only a small fraction of the longer-range al-Hussein ballistic missiles it had in 1991, the relatively few missiles still in Iraqi hands can be primitively armed with chemical and biological weapons (CBW). In 1991, Iraqi forces were pre-delegated with the authority to launch missiles only if nuclear weapons were used against the regime or Baghdad was threatened. With regime-change a declared US goal this time around, however, Saddam may be more inclined to use CBW against both military targets and civilian populations. Especially worrisome to US war planners is the possibility that Israel could retaliate against Iraqi missile strikes, based on an assessment that Israel's regional deterrence strategy could not bear the restraint it practiced in 1991, when Iraq launched 39 conventionally armed al-Hussein missiles against Israeli cities. Such retaliation would risk an enlargement of the conflict that would be difficult to contain, intensify anti-American feeling in the Muslim world and increase the threat of transnational terrorist attacks. Thus, the effectiveness of US and Israeli defences against the Iraqi missile threat would be a key strategic factor in a US–Iraq war.
The Iraqi threat
Iraq's capacity to deliver biological or chemical weapons against regional targets in the Middle East rests primarily with a small number (not more than a few dozen) of covertly retained al-Hussein ballistic missiles – an extended range version of the Scud-B missile – that are capable of delivering a 500-kilogramme payload at a range of 650 kilometres. Longer ranges could be achieved with smaller payloads. (The small force of al-Samoud ballistic missiles that Iraq may also possess – the range of which Baghdad has, according to the UK government, extended from 150 to 200km – could not practically threaten regional targets unless Iraq could deploy them in the northern or southern no-fly zones.) Iraq admitted to the UN's Special Commission that in late 1990 it had filled 25 warheads with anthrax, botulinum toxin and aflatoxin, and 50 others with the mixed chemical agents sarin and cyclosarin. Evidence also suggests that some missile warheads were filled with the nerve agent VX.
There is little doubt that Iraq has a stockpile of covertly retained and newly produced biological and chemical agents of these types sufficient to use with its al-Hussein missiles. There is a very remote possibility that Iraq has obtained or preserved smallpox virus and weaponised small quantities. The extent to which Iraq may have improved on its Gulf War-era capacity to disseminate such agents remains an open question. Iraq had, by this time, fitted within the warhead a stainless steel container for biological agents and an aluminium container for chemical agents, with a capacity of about 145 litres of liquid agent. On impact with the ground, the warhead would detonate, disseminating the agent by means of explosive force. Such a crude method of dissemination would destroy perhaps 90% of a biological agent, meaning less than 15 litres would remain to contaminate an area of probably a few hundred metres in diameter. Some additional dissemination might occur as a by-product of a BW 'cloud' drifting downwind, but the area covered by the agent would be subject to the vagaries of several unpredictable factors, including wind, sunlight and droplet size. Given that much higher volumes of chemical agent would be needed to achieve a level of effectiveness comparable to BW, such a crude dissemination method severely compromises CW use.
It appears doubtful that Iraq has achieved breakthroughs in the difficult tasks of ballistic-missile proximity fusing and the dissemination of CBW agents using submunitions. But there is a more substantial possibility that Iraq has transformed some of its fleet of 78 Czech L-29 trainer aircraft (acquired over 20 years ago) into unmanned drones capable of long-range autonomous flight. An unmanned aircraft's flight stability, in turn, permits it to become an effective means of releasing and spraying an agent along a line of contamination. While perhaps only 10% of, say, liquid anthrax – less than 15 litres – might survive the explosive impact of an Iraqi ballistic missile, nearly the entire capacity of an L-29 spray tank – 300 litres – would be available for dissemination.
Prior to the end of inspections in 1998, UN inspectors observed that Iraq had succeeded in converting several L-29s into radio-controlled unmanned aerial vehicles (UAVs) capable of flying about 70 km. Iraq could have converted these trainers from being merely radio-controlled to being autonomously controlled – where the UAV flies itself according to a set of pre-programmed instructions – with commercially available UAV flight-management systems that are not subject to export restrictions. Further, in a bombing raid during Operation Desert Fox in December 1998, British pilots identified up to a dozen L-29 UAVs outfitted with wing-mounted 300-litre spray tanks. How many of these particular UAVs survived the 1998 bombing raid and how many others might have been cannibalised from the original 78 trainers is unknown. Earlier this year, the CIA reported that a new series of Iraqi L-29 aerial tests occurred during 2000, suggesting that the programme is still active. If 10 converted L-29s were outfitted and employable over one-way ranges of more than 600 km, Iraq would have the capacity to deliver with each L-29 more than 20 times as much chemical or biological agent than its al-Hussein ballistic missile could deliver. The problem of clogged sprayers, particularly with wet agents, could impede agent dissemination but is by no means insurmountable.
Missile defences
Finding and attacking Iraqi mobile launchers before their missiles are launched – in military parlance, attack operations or counterforce – is naturally preferable to in-flight interception as a method of missile defence. Yet, despite the availability of Global Hawk and Predator UAVs, and the prospect that E-8 Joint-STARS ground-surveillance aircraft might operate over western Iraq, the United States' capacity to neutralise mobile launchers is not significantly better today than it was during Operation Desert Storm, when not one Iraqi launcher was destroyed. In the absence of wide-area and persistent surveillance (preferably via space-based radar), breakthroughs in automated target identification to reduce false alarms, and significant reduction in the sensor-to-shooter decision cycle, effective counterforce will remain elusive.
There are, of course, far less elegant forms of counterforce than air power. A US-led coalition could opt for a massive deployment of ground forces in northwestern Iraq from the very beginning of any campaign. Alternatively, a lower-profile operation could conceivably be staged out of Jordan using special operations units to work in tandem with air power. In either case, the initial counterforce objective would be to compel Iraqi mobile missile launchers to operate outside launch points that would enable strikes against Israel, and the ultimate objective to find and destroy all Iraqi launchers and missiles. The first option would have the greatest likelihood of success.
Israel would be operating from a much stronger position than it was during the 1991 Gulf War. Iraq has far fewer missiles in its arsenal. More importantly, Israel has acquired a missile-defence capability. During the Gulf War, the American Patriot PAC-2 system was rushed from an experimental state into the field. Designed to intercept aircraft, and then upgraded to handle shorter-range ballistic missiles as well, Patriot's radar experienced difficulty distinguishing real missiles from missile debris created when Iraqi Scuds broke up after re-entering the atmosphere. PAC-2 missiles proved much better at knocking incoming missiles off course, which explains why their success rate in Saudi Arabia (defending small point targets like airbases) was much better than in Israel (protecting large urban areas). Since the Gulf War, with US cooperation, Israel has developed the Arrow-2 missile-defence system, which was purposefully designed to handle ballistic missiles with ranges of perhaps as much as 1,500 km and to intercept the incoming missiles at a much higher altitude than Patriot. Thus, the Arrow-2 can destroy the missile before any inadvertent atmospheric break-up, further away from Israeli territory (which is especially desirable if the missile carries a CBW warhead).
To provide a nationwide missile defence, Israel intends to deploy three batteries of Arrow-2 missiles by 2010. At present, two have been deployed, and should furnish adequate coverage against Iraqi missile threats. Israel has also enhanced its attack warning capability, which is critical to initiating timely passive defence measures (such as donning protective masks). Israel now has two intelligence satellites – the Eros and Ofeq-5 – that furnish independent evidence of regional threat activities. The Arrow's Green Pine radar further provides Israel with its own source of missile launch information, which can be enhanced when combined with US satellite-warning data.
The Patriot PAC-2 system will both complement Israel's Arrow deployments by completing a two-tier missile-defence system, and furnish point-defences for Israeli cities and other strategically important targets, such as its Negev Nuclear Research Centre. It will also provide point-defences for US military forces and selected population centres in threatened regions. The latest and most radical Patriot upgrade, called PAC-3, which uses hit-to-kill technology rather than an exploding warhead, will greatly improve area coverage and lethality, but it is still under development. An improved version of the 1991 Gulf War PAC-2 must carry the missile-defence burden for US-led forces and their regional partners. The new PAC-2 employs a Guidance Enhanced Missile (GEM) that improves lethality against Scud-class missiles and carries a radar upgrade doubling its power and enhancing target discrimination. Israel is likely to receive the GEM for its existing PAC-2 units and additional PAC-2 batteries as war looms closer. The US has already accelerated delivery of around 10 additional PAC-2 batteries for deployment around Ali al-Salem and Ahmad al-Jaber airbases in Kuwait, from which US and British fighters would operate should war occur. US and Kuwaiti-manned PAC-2 batteries already protect population centres in Kuwait.
Performance prospects
The inherent limitations of the Iraqi missile threat – few missiles, small warheads, and probably explosive dissemination – suggest that only unprepared civilian populations face any potentially serious risk. Based on computer simulations, Israeli defence officials expect a success rate of over 90% from their two-tier missile defence system. Such simulations do not always mirror the real world, however. Although Israel's Arrow has succeeded in eight of its last nine tests, moving abruptly from the test range directly to the real world without extensive operational testing carries enormous uncertainties and risks. Prudent military planners would conclude that a CBW-armed Iraqi ballistic missile could conceivably get through Israeli or US missile defences, or spread its agent after interception. Should Saddam's missile commanders choose to obey an early launch order, particularly one involving CBW, Israeli and US missile defences would be severely tested in unfamiliar conditions.
Iraq's possible use of UAVs armed with CBW dispensers is a worrisome wildcard. L-29 UAVs could be hidden and launched from grassy, sandy or even waterlogged airstrips. Low-flying UAVs would present difficult problems for dual-mode air defences like PAC-2. During the 1991 Gulf War, coalition air forces quickly eliminated the Iraqi aircraft threat, allowing PAC-2 batteries to train their radars exclusively on high-angle Scuds. But in the next conflict, PAC-2 batteries would need to defend against both high- and low-angle threats and, in the case of US batteries, separate returning friendly aircraft from any low-flying Iraqi UAVs. In simulations, such stressing air-defence environments routinely produce unacceptable levels of friendly-fire casualties. US Avenger air-defence units, consisting of Stinger missiles on wheeled vehicles, may ameliorate this problem, but unprotected civilian populations would remain at risk from L-29 UAVs.
Finally, perceived strategic imperatives and vehement domestic opinion could impel the Israeli government to respond proportionally to any Iraqi attack, no matter how successful its missile defences perform. Given the uncertainty of sophisticated missile defences not yet battlefield tested, the demonstrated Iraqi interest in and capability of converting L-29s into CBW delivery systems, and the brittleness of Israeli restraint, a rapid and successful invasion remains the most desirable means of eliminating Iraq's missile threat from both a military and political point of view.
