As the world's attention focuses more and more on the war in Iraq, now expected to begin within three or four days, Israeli defense experts are mulling over the question of when to instruct the public to prepare sealed rooms. It is feared that Iraq may pre-empt, or react to, an American strike by launching missiles at Israel, possibly with chemical or biological warheads. Israeli military leaders have been saying for months that the danger of such an attack is very low. U.S. President George Bush, British Prime Minister Tony Blair, and Spain's Prime Minister Jose Aznar held a summit meeting today in the Azores, as a show of unity among the lone major allies that support ridding the world of Saddam. Germany, one of the three major anti-war countries, has ordered its citizens to leave Iraq.