The PAC-2 missile was the first anti-missile missile in history to be used successfully in combat. It works by closely approaching and then exploding near its target. Coming into service for the first time in 1991with U.S forces in Iraq in Operation Desert Storm, 158 PAC-2s were launched against Iraqi Scuds both in Saudi Arabia and in Israel. The effectiveness of the system, however, was low, rated later by the U.S. Army as 70% in Saudi Arabia and just 40% in Israel. Other analysis reported figures even lower.
One problem discovered with the method of proximity explosion during the Gulf War was the tendency of the PAC-2 to not totally destroy its target, but rather to push it off course. Since that time, the original PAC-2 system has been upgraded by Raytheon, to improve its guidance system and kill probability.
Israel currently deploys several units of the PAC-2 system. During the Second Lebanon War in the summer of 2006, a number of these were positioned in Haifa and Tzfat, but, for reasons which are not clear, they were not used during the war.