Gormley, Dennis M. "Missile Defence Myopia: Lessons from the Iraq War". Survival, Vol. 45, No. 4 (2003): 61-86.

Gormley, Dennis M. "Missile Defence Myopia: Lessons from the Iraq War". Survival, Vol. 45, No. 4 (2003): 61-86.

• The capture of Baghdad from Iraqi forces in 21 days was seen as a triumph for Secretary of Defense Donald Rumsfeld's adoption of 'network centric warfare', that enabled the US to bring combined offensive fire across multiple theaters of operations. It also created a sense that the US armed forces were invincible (61).
• US defensive weapons systems had a mixed record in the Invasion of Iraq, as they were able to successfully intercept 9 Iraqi ballistic missiles (61), but failed to detect or failed to intercept 4 of out 5 Iraqi HY-2 Seersucker cruise missiles (66). The US Patriot missile batteries were also responsible for a number of friendly fire incidents (61, 68).
• Part of this difference may be that in 1991, Iraq used Scud missiles that had been hastily modified in the late 1980s to increase their range. These modifications made their flight paths irregular and difficult to target. In the 2003 war, Iraqi missiles were standard and short-range (64-65). Differences in combat environment are also responsible for an increase in friendly fire incidences, as in 1991, Patriot system could focus on the unique signatures of ballistic missiles, whereas in 2003, the Patriot batteries were responsible for targeting ballistic missiles, cruise missiles, Iraqi aircraft, and unmanned drones, many of which have radar signatures similar to US aircraft (68).
• The Patriot batteries also received a number of false alarms of impending attacks, forcing crews to don hazmat suits due to the threat of Iraqi chemical or biological weapons. This policy was wise in light of the threat of such attacks and the inability of contemporary radar technologies to positively verify cruise missile signatures, but it did have a negative effect on the operational capacity of the Patriot batteries (65-66).
• The Pentagon was been aware of deficiencies in US missile defense systems since the 1990s and these same deficiencies, including system errors in the friendly force tracking software of Patriot batteries, were criticized by the Senate in 2002 (62). Moreover, these same deficiencies in friendly force tracking systems were discovered by a National Research Council study in 1996 (68).
• The USA needs to respond to the inadequacy of the Patriot's tracking and identification systems by overhauling the disparate tracking methods used by different weapons systems and adopting a unified command, control, and communication system for all service branches through the Single Integrated Air Picture. The physical limitations of the Patriot's own detection system, due to the curvature of the Earth, must also be dealt with by supplementing Patriot batteries with aerial sensors (76), potentially by making the Air Force responsible for all detection, targeting, and fire control duties (77).
• A move towards this is blocked by the fact that funding and execution of Pentagon priorities still takes place entirely at the service branch level, meaning broad cooperation on implementation is difficult and subject to inter-service rivalries. It may become necessary to create a single inter-service agency under the Pentagon responsible for cruise missile defense, similar to the Missile Defense Agency for ballistic missile defense (78-79).
• The deficient performance of US missile defense systems against cruise missiles, ultralight aircraft, and unmanned drones in the Invasion of Iraq is bad news because those systems can effectively constitute a 'poor man's airforce'. Enemies of the USA are increasingly likely to turn towards these options after the 2003 war because it demonstrated relatively poor American performance against cruise missiles and a significant improvement in American missile defense capabilities against ballistic missiles since 1991 (62-63). 
• This transition is also encouraged by a broader move away from aerial assets, as airbases and aircraft can be easily targeted and destroyed by US forces, and towards missiles, which can be hidden and launched from mobile platforms (71).
• The most effective way to accomplish this would be to transform anti-ship cruise missiles or small drones into land-based missile systems. These systems would be fast, effective in delivering large payloads, especially of chemical or biological weapons, and very low cost. The main present obstacle to their construction is the difficult of remotely piloting unmanned drones and of automating these functions (74).
• The development of such a 'poor man's airforce' would necessitate global countermeasures to secure American military assets and the homeland, as lack of detection means that US Navy assets are exposed at port around the world and the American coastline is unguarded against a potential cruise missile attack from just beyond our territorial seas (75). Even limited improvement could cost between $30 billion and $40 billion (78).
• The greatest danger is that these cruise missile attacks will be so much cheaper than the missile defense measures needed to counter them (75). This means that the core issues posed by the adoption of cheap cruise missiles remain unsolved; the USA still needs to make missile defense less expensive and develop radar capable to tracking slow-flying targets (77).
• The original Patriot system deployed against Iraq in 1991 was rushed into deployment and performed poorly. The main issue was that the proximity fuse fired when the missile was too distant to destroy the projectile, meaning that the Patriot system failed to destroy the missile, either doing nothing or merely altering its course. These original batteries intercepted only 9% of Iraqi missiles (63).
• Since 1991, three new interceptor systems have been developed for the Patriot system, with the battery selecting which interceptor is most appropriate for the given target. These interceptors are the PAC-2 Guidance Enhanced Missile [PAC-2 GEM], an improvement on the original missile that actually explodes missiles; the PAC-2 GEM-Plus, which focuses on intercepting smaller targets, like cruise missiles; and the PAC-3, which fires four smaller missiles to destroy the entire target, although this is more expensive, costing $12 million to $15 million per shot (64).
• During the 2003 Invasion of Iraq, Patriot missile batteries were deployed in Kuwait, Qatar, Bahrain, Saudi Arabia, Israel, and within NATO forces in Turkey, although the Kuwaiti systems were moved forward as the front progressed toward Baghdad. These Patriot batteries were supplied with information by an Aegis cruiser in the Persian Gulf and the Cobra Judy naval radar system (63).
• Patriot systems in the 2003 Invasion of Iraq fired a minimum of two sequential missiles at a target, and sometimes more, to increase the likelihood of interception. However, in most cases the first missile destroyed the target projectile (65).
• A full list of combat incidences involving the Patriot system in the 2003 Iraq War is available on pages 69 and 70.
• Although American officials tried to downplay the threat posed by Seersucker missiles, they were arguably more dangerous considering Iraq's chemical and biological weapons programs, as their horizontal flight path is more amenable to disseminating chemical or harmful biological agents over a large area (72). Its older design also lends more readily to conversion into a land-based missile (73).
• The use of Seersucker missiles in this manner still pose issues, however, primarily in connecting their targeting systems to available GPS technology, and in replacing the Seersucker's rocket engine with a suitable jet engine. The first of these issues is easier to surmount with the growing available and sophistication of GPS and unmanned drone technology (73).
• The likelihood of small cruise missiles and drones becoming a new form of aerial attack against US forces is largely determined by the effectiveness of the Missile Technology Control Regime. However, the sale of the Black Shaheen stealth cruise missile to the UAE by Britain and France against the objections of the USA does not bode well for the future of the Regime, nor do the desires of China and Russia to expand their missile export markets (75).
• Thus far, the Missile Technology Control Regime has been largely successful in preventing the spread of missile and dual use technology and materials, with ballistic missile proliferation largely limited to Scud missile technology from the 1950s. It has been less effective in preventing the proliferation of cruise missile technology, as its restrictions on flight management systems are too narrow to effectively prevent proliferation or the ability of states to convert anti-ship cruise missiles to attack land-based targets, although member states pledged to tighten these restrictions at the annual meeting in Warsaw in September 2002 (79). These provisions could, however, be further improved by restricting jet engines and technologies that enhance stealth capabilities (80).
• "In the aftermath of 11 September NORAD had no internal air picture, nor were its radar assets linked with those of the Federal Aviation Administration" (78).