Persian Gulf War (1991)
Trial by fire
Prior to the First Gulf War, ballistic missile defense was an unproven concept in war. During Operation Desert Storm, in addition to its anti-aircraft mission, Patriot was assigned to shoot down incoming Iraqi Scud or Al Hussein short range ballistic missiles launched at Israel and Saudi Arabia. The first combat use of Patriot occurred 18 January 1991 when it engaged what was later found to be a computer glitch. There were actually no Scuds fired at Saudi Arabia on 18 January. This incident was widely misreported as the first successful interception of an enemy ballistic missile in history.
Throughout the war, Patriot missiles attempted engagement of over 40 hostile ballistic missiles. The success of these engagements, and in particular how many of them were real targets, is still controversial. Postwar video analysis of presumed interceptions by MIT professor Theodore Postol suggests that no Scud was actually hit; this analysis is contested by Peter D. Zimmerman, who claimed that photographs of the fuselage of downed SCUD missiles in Saudi Arabia demonstrated that the SCUD missiles were fired into Saudi Arabia and were riddled with fragments from the lethality enhancer of Patriot Missiles.
Failure at Dhahran
On 25 February 1991, an Iraqi Scud hit the barracks in Dhahran, Saudi Arabia, killing 28 soldiers from the U.S. Army's 14th Quartermaster Detachment.
A government investigation revealed that the failed intercept at Dhahran had been caused by a software error in the system's handling of timestamps. The Patriot missile battery at Dhahran had been in operation for 100 hours, by which time the system's internal clock had drifted by one-third of a second. Due to the missile's speed this was equivalent to a miss distance of 600 meters.
The radar system had successfully detected the Scud and predicted where to look for it next. However, the timestamps of the two radar pulses being compared were converted to floating point differently: one correctly, the other introducing an error proportionate to the operation time so far (100 hours). The difference between the two was consequently wrong, so the system looked in the wrong part of the sky and found no target. With no target, the initial detection was assumed to be a spurious track and the missile was removed from the system. No interception was attempted, and the Scud impacted on a makeshift barracks in an Al Khobar warehouse, killing 28 soldiers.
Two weeks earlier, on 11 February 1991, the Israelis had identified the problem and informed the U.S. Army and the PATRIOT Project Office, the software manufacturer. As a stopgap measure, the Israelis had recommended rebooting the system's computers regularly. The manufacturer supplied updated software to the Army on 26 February.
There had previously been failures in the MIM-104 system at the Joint Defense Facility Nurrungar in Australia, which was charged with processing signals from satellite-based early launch detection systems.
Success rate vs. accuracy
On 15 February 1991, President George H. W. Bush traveled to Raytheon's Patriot manufacturing plant in Andover, Massachusetts, during the Gulf War, he declared, the "Patriot is 41 for 42: 42 Scuds engaged, 41 intercepted!" The President's claimed success rate was thus over 97% to that point in the war. The U.S. Army claimed an initial success rate of 80% in Saudi Arabia and 50% in Israel. Those claims were eventually scaled back to 70% and 40%.
On 7 April 1992 Theodore Postol of the Massachusetts Institute of Technology, and Reuven Pedatzur of Tel Aviv University testified before a House Committee stating that, according to their independent analysis of video tapes, the Patriot system had a success rate of below 10%, and perhaps even a zero success rate.
Also on 7 April 1992 Charles A. Zraket of Harvard's Kennedy School of Government and Peter D. Zimmerman of the Center for Strategic and International Studies testified about the calculation of success rates and accuracy in Israel and Saudi Arabia and discounted many of the statements and methodologies in Postol's report.
According to Zimmerman, it is important to note the difference in terms when analyzing the performance of the system during the war:
- Success Rate – the percentage of Scuds destroyed or deflected to unpopulated areas
- Accuracy – the percentage of hits out of all the Patriots fired
- In accordance with the standard firing doctrine on average four Patriots were launched at each incoming Scud – in Saudi Arabia an average of three Patriots were fired. If every Scud were deflected or destroyed the success rate would be 100% but the Accuracy would only be 25% and 33% respectively.
The Iraqi redesign of the Scuds also played a role. Iraq had redesigned its Scuds by removing weight from the warhead to increase speed and range, but the changes weakened the missile and made it unstable during flight, creating a tendency for the SCUD to break up during its descent from Near space. This presented a larger number of targets as it was unclear which piece contained the warhead.
What all these factors mean, according to Zimmerman, is that the calculation of "Kills" becomes more difficult. Is a kill the hitting of a warhead or the hitting of a missile? If the warhead falls into the desert because a PATRIOT hit its Scud, is it a success? What if it hits a populated suburb? What if all four of the engaging PATRIOT missiles hit, but the warhead falls anyway because the Scud broke up?
According to the Zraket testimony there was a lack of high quality photographic equipment necessary to record the interceptions of targets. Therefore, PATRIOT crews recorded each launch on standard definition videotape, which was insufficient for detailed analysis. Damage assessment teams videotaped the Scud debris that was found on the ground, and crater analysis was then used to determine if the warhead was destroyed before the debris crashed or not. Furthermore, part of the reason for the 30% improvement in success rate in Saudi Arabia compared to Israel is that the PATRIOT merely had to push the incoming Scud missiles away from military targets in the desert or disable the Scud's warhead in order to avoid casualties, while in Israel the Scuds were aimed directly at cities and civilian populations. The Saudi Government also censored any reporting of Scud damage by the Saudi press. The Israeli Government did not institute the same type of censorship. Furthermore, PATRIOT's success rate in Israel was examined by the IDF (Israel Defense Forces) who did not have a political reason to play up PATRIOT's success rate. The IDF counted any Scud that exploded on the ground (regardless of whether or not it was diverted) as a failure for the Patriot. Meanwhile, the U.S. Army who had many reasons to support a high success rate for PATRIOT, examined the performance of PATRIOT in Saudi Arabia.
Both testimonies state that part of the problems stem from its original design as an anti-aircraft system. PATRIOT was designed with proximity fused warheads, which are designed to explode immediately prior to hitting a target spraying shrapnel out in a fan in front of the missile, either destroying or disabling the target. These missiles were fired at the target's center of mass. With aircraft this was fine, but considering the much higher speeds of TBMs, as well as the location of the warhead (usually in the nose), PATRIOT would most often hit closer to the tail of the Scud due to the delay present in the proximity fused warhead, thus not destroying the TBM's warhead and allowing it to fall to earth.
In response to the testimonies and other evidence, the staff of the House Government Operations Subcommittee on Legislation and National Security reported, "The Patriot missile system was not the spectacular success in the Persian Gulf War that the American public was led to believe. There is little evidence to prove that the Patriot hit more than a few Scud missiles launched by Iraq during the Gulf War, and there are some doubts about even these engagements. The public and the United States Congress were misled by definitive statements of success issued by administration and Raytheon representatives during and after the war."
A Fifth Estate documentary quotes the former Israeli Defense Minister as saying the Israeli government was so dissatisfied with the performance of the missile defense, they were preparing their own military retaliation on Iraq regardless of U.S. objections. That response was canceled only with the ceasefire with Iraq.
Operation Iraqi Freedom (2003)
Patriot was deployed to Iraq a second time in 2003, this time to provide air and missile defense for the forces conducting Operation Iraqi Freedom (OIF). Patriot PAC-3, GEM, and GEM+ missiles both had a very high success rate, intercepting Al-Samoud 2 and Ababil-100 tactical ballistic missiles. However, no longer-range ballistic missiles were fired during that conflict. The systems were stationed in Kuwait and successfully destroyed a number of hostile surface-to-surface missiles using the new PAC-3 and guidance enhanced missiles. Patriot missile batteries were involved in three friendly fire incidents, resulting in the downing of a Royal Air Force Tornado and the death of both crew members, Flight Lieutenant David Rhys Williams and Flight Lieutenant Kevin Barry Main, on 23 March 2003. On 24 March 2003, a USAF F-16CJ Fighting Falcon fired a HARM anti-radiation missile at a Patriot missile battery after the Patriot's radar had locked onto and prepared to fire at the aircraft, causing the pilot to mistake it for an Iraqi surface-to-air missile system. The HARM missed its target and no one was injured and the Patriot Radar was examined and continued to operate but was replaced due to a chance that a fragment may have penetrated it and gone undetected. On 2 April 2003, 2 PAC-3 missiles shot down a USN F/A-18 Hornet killing U.S. Navy Lieutenant Nathan D. White of VFA-195, Carrier Air Wing Five.
Service with Israel
Israeli Patriot battery (together with Iron Dome battery, left) in display for United States Secretary of Defense Chuck Hagel, 2014.
Today the Israeli Air Defense Command operates MIM-104D Patriot (PAC-2/GEM+) batteries with Israeli upgrades. The Israel Defense Forces' designation for the Patriot weapon system is "Yahalom" ("diamond" in Hebrew).
Operation Protective Edge (2014)
During Operation Protective Edge, Patriot batteries of the Israeli Air Defense Command intercepted and destroyed two unmanned aerial vehicles launched by Hamas. The interception of a Hamas drone on 14 July 2014 was the first time in the history of the Patriot system's use that it successfully intercepted an enemy aircraft.
Syrian civil war (2014)
On 31 August 2014, a Syrian unmanned aerial vehicle was shot down by an Israeli Air Defense Command MIM-104D Patriot missile near Quneitra, after it had penetrated Israeli airspace over the Golan Heights. Nearly a month later, on September 23, a Syrian Air Force Sukhoi Su-24 was shot down on similar circumstances.