The US and Israeli militaries will launch their biggest joint missile defense drill yet on Wednesday, in the shadow of mounting missile threats from Iran, Hizbullah and Syria, and growing regional tension over Teheran's nuclear program. The Juniper Cobra 10 exercise will test responses to a range of incoming projectiles. More than 1,000 members of the US military's European Command and a similar number of IDF soldiers will participate, the IDF announced on Tuesday. The two militaries will test Israel's Arrow 2 Theater Ballistic Missile Defense System, and the American Navy's AEGIS Ballistic Missile Defense System. US Patriot advanced capability anti-missile missiles will also be deployed. Seventeen US Navy ships have cruised into Israel's territorial waters for the exercise, and will be visible from the coast. The fleet consists of missile ships that will fire dummy projectiles to test defenses, and radar ships that will play an integral part in the exercise. Air force planes will play a variety of roles during the drill. Radar stations have been erected around the country, and Israel's Green Pine and Super Green Pine missile detection systems will be activated. The US-made Forward Based X-band Tactical radar, situated in the Negev, which has long-range missile detection system, will also come into play. The X-band radar works in conjunction with the Arrow missile defense, while also transmitting data to a US joint tactical ground station. The two countries have held smaller combined drills in the past. American military officials arrived in Israel months ago to begin groundwork for the exercise, which has been in the planning for two years. Over the past three months, preparations reached an intensive phase. Defense sources said they expect the drill to be a success, since the systems have all been successfully tested before. Iran test-fired Shihab 3 long-range missiles at the end of last month, before holding a first round of nuclear talks with Western powers, in a move widely seen as an attempt to ward off a military strike on its nuclear sites. Teheran said the Shihab 3 it tested had a range of 2,000 km., putting Israel and US military bases in the Middle East in reach. In May, Iran test-fired a solid-fuel mid-range missile, which reportedly is also able to reach Israel. In April, Israel successfully tested its Arrow 2 anti-ballistic missiles system, which is designed to cope with an increased Iranian missile capability. Defense sources said in February that Iran had added a new missile to its operational ballistic arsenal - the BM25. Purchased by Iran from North Korea in 2008, the BM25 missile has a range of more than 2,500 km., and can be launched quickly from a mobile launcher. Its longer range means that it has a faster flight speed, requiring the Arrow defense system to be upgraded to deal with the new threat. Engineers have been working to speed up the Arrow 2 system's "decision-making process," which begins when missiles are fired at Israel, and to launch interceptor missiles in less time than before. Teheran's growing ballistic capability means that in addition to the threat of conventional missile attacks, the Islamic republic is improving its delivery capability for a nuclear weapon. "Most of Iran's ballistic missiles can carry nuclear warheads," a defense source said in February. The source added that people on the ground would be safe in the event of a nuclear warhead being intercepted in midair by the Arrow system. "There's a very high likelihood that nothing will happen if a missile carrying a nonconventional weapon is intercepted," the source said. The Arrow shield has been designed to deal with barrages of missiles that include a real nuclear warhead surrounded by dummy warheads to confuse the system. Even if the Arrow fails to directly strike its target, "a miss will still be a hit," the defense source said.