By Dan Williams
JERUSALEM (Reuters) - Israeli leaders holed up in a new underground nuclear bunker on Wednesday as part of annual maneuvers to prepare for a possible missile war with Iran, Syria and their Lebanese and Palestinian guerrilla allies.
Officials said it was the first time the security cabinet, headed by Prime Minister Benjamin Netanyahu, had tested the "National Management Center" carved out beneath the government complex in Jerusalem over the past decade.
The bunker includes living quarters as well as command facilities. It can be accessed through the western foothills leading to the coastal metropolis of Tel Aviv.
"This is the proper place from which to run the State of Israel in wartime," Homefront Defense Minister Matan Vilnai told Army Radio in an interview.
Israel instituted increasingly sweeping civil defense drills after the 2006 Lebanon war in which Hezbollah fighters fired thousands of short-range rockets at its northern towns.
There have been similar salvoes from Hamas and other Palestinian factions in the Gaza Strip to the south, and Israeli officials say a future war could involve non-conventional missile strikes by Syria and Iran.
Wednesday's exercise, dubbed "Turning Point 5," envisaged heavy shelling and thousands of dead and wounded on several Israeli fronts. Police and medics practiced mass-casualty incidents and air raid sirens were scheduled to sound twice.
"It is certainly an extreme scenario (although) we assume that our enemies would not dare to operate this way, given our deterrent power," Vilnai said.
Reputed to have the Middle East's only atomic arsenal, Israel bombed an Iraqi reactor in 1981 under what it called a policy of denying foes the means to threaten its destruction.
Israel launched a similar sortie against Syria in 2007 but its veiled threats to tackle Iran's remote and fortified uranium enrichment sites have often been dismissed as bluster given the tactical challenges involved. World powers say they prefer a negotiated resolution with Iran, which denies seeking the bomb.
Disclosures of the Jerusalem bunker's existence prompted some Israelis to question whether their country, which has also been developing an elaborate ballistic missile shield, was taking a more passive approach to potential nuclear threats.
Officials say that providing Israeli leaders with a secret haven from which to respond to attacks would in itself discourage, or at least contain, any future war.
(Editing by Alison Williams)