The missile barrage is launched simultaneously in three countries. Scud Cs from Syria, Shihab-3s from Iran and shorter-range Zelzals from Lebanon. As alarms sound, air force officers huddle in front of their large plasma computer screens, wipe the sweat off their brows, clear their throats and get to work. In the "cube" - the heavily fortified Arrow missile defense command center in the Palmahim Air Force Base - a young lieutenant punches a series of buttons on his keyboard, to identify the incoming threats. He then rattles them off to the rest of the room. "There is a launch in the East," he says, as the letters ENG - standing for the Shihab-3's engine - pop up on his screen, accompanied by a "bleep." "And another one from Syria," he adds, as a second bleep sounds, and the letters SD appear - standing for Scud D, Syria's largest ballistic missile. Across the cube - officially called the Citron Tree - another junior officer watches a satellite image pop up on his screen, with an arrow pointing at the incoming missile's projected landing site. One missile is headed toward Petah Tikva, three others toward Jerusalem and two toward Dimona, home to the country's nuclear reactor. These images are transmitted directly to the IDF Home Front Command, which immediately sets off air-raid sirens and dispatches rescue workers to the projected sites. After 10 enemy missiles are in the air, quickly picking up speed as they hone in on their targets, a row of officers on another side of the room hit the F2 buttons on their keyboards, launching close to two dozen Arrow 2 interceptors from Palmahim, and another battery deployed at Ein Shemer in the North. THIS SCENARIO - simulated Tuesday at Palmahim - is one of the IDF's worst nightmares: a simultaneous Iranian and Syrian missile barrage, possibly carrying nuclear or non-conventional warheads, and all heading toward Israel, with only minutes to be intercepted. While the Home Front Command is prepared to deal with a potential missile fallout, the country is banking on the Arrow to prevent that from being necessary. But with Iran continuing to defy the international community - it rejected the European Union's incentive package this week - the possibility of a military strike against Teheran's nuclear facilities is rumored to be growing. In such an event, Iran would likely respond by firing long-range Shihab missiles at Israel - even if the IDF is not directly behind the strike. AS THE air force ran the above Arrow simulation, Lt.-Gen. Henry A. Obering III - director of America's Missile Defense Agency - was meeting with Defense Ministry officials in Tel Aviv. During the talk, he reportedly declared the US Defense Department's intention to recommend that the Congress contribute funding for the development and production of the Arrow 3 - the next generation, in terms of speed, range and altitude, of Israeli missile interceptors. According to defense officials, the new Arrow will become operational by 2012. Still, the IDF is confident that the current system is capable of protecting the country. "We have good answers to the threats and scenarios that we foresee in the region," OC Air Defense Forces Brig.-Gen. Daniel Milo said, following the simulation at Palmahim. "There is no such thing as a 100-percent solution, but the way we provide an answer to ballistic missiles is improving all the time." As the Iranians strive for missile advances - Teheran claims its missiles have multiple warheads, advanced guidance systems and decoy-discharge capabilities - Milo and his men are in a constant race to be at least one step ahead. To meet this goal, they face a number of growing challenges. First is ensuring that the Arrow's Green Pine radar system can detect incoming missiles with enough time to spare. The time required depends on the type of missile and where it is launched, but ranges anywhere from around 15 seconds to several minutes. The Arrow teams in Ein Shemer and Palmahim do not have to wait for a real attack before they can test their systems. Iran's missile show last month - during which it claimed to test-fire nine new, advanced ballistic missiles - was detected by the Green Pine radar, and closely followed in the cube as if missiles were actually on their way to Tel Aviv. IAF officers said this week they believe that, where missile detection is concerned, the future lies in space-based platforms like satellites, which can be made available for the Arrow missile defense system at a moment's notice. Israel operates several advanced spy satellites - Ofek, Eros and TecSar - that can also detect and track missile launches. Last week, US Secretary of Defense Robert Gates told Defense Minister Ehud Barak that America was prepared to deploy the powerful X-band phased radar to enhance Israeli missile-detection systems. MISSILE DEFENSE systems have a twofold purpose in IDF strategy: preventing civilian casualties and providing the government with better diplomatic maneuverability. Missile defense is one of the issues that stand at the core of Israeli-US defense ties, as Obering's visit demonstrated. This dates back 17 years when, ahead of the Gulf War in 1991, US Patriot missile systems were deployed here to help defend against Iraqi Scuds. This intimate relationship continues, with the US funding the Arrow, and Boeing's involvement in the development of the defense system's interceptor. Ahead of a possible showdown with Iran, this relationship has been enhanced with the potential deployment of new, more-advanced US-made missile defense systems here. While such a deployment would require presidential approval, in recent years the American and Israeli air forces have held a number of simulations and drills - called Juniper Cobra - to prepare for the possibility of Aegis missile ships or THAAD (terminal high-altitude area defense) systems being deployed here. Israel and the US have created a special mechanism that would enable the rapid deployment of the American systems and their hookup to existing infrastructure. The person who would command all the systems would be OC Air Force Maj.-Gen. Ido Nehushtan, who would give orders to the American Aegis ship or THAAD teams. IN RESPONSE to his assessment of a growing missile threat, upon taking up his post as defense minister following the Second Lebanon War, Barak called for the urgent development of a multi-layered defense plan. To prepare for this, Milo prepared a three-step training and procurement plan for his unit, which hopes to receive the Iron Dome anti-Kassam system by 2010, as well as the Arrow 3 and David's Sling for medium-range missiles by 2012. Additional Arrow batteries will be deployed throughout the country by the end of the year. "Good answers" will be getting better.