Last week in Washington, Robert Gates - US President George W. Bush's (since confirmed) nominee for defense secretary - in the middle of his Senate confirmation hearings, was asked why he thought Iran might be seeking nuclear weapons. "They are surrounded by powers with nuclear weapons: Pakistan to the east, the Russians to the north, the Israelis to the west and us in the Persian Gulf," was his answer. This week, in an interview with German TV at his Jerusalem residence, Prime Minister Ehud Olmert said: "Iran openly, explicitly and publicly threatens to wipe Israel off the map. Can you say that this is the same level, when they [Iran] are aspiring to have nuclear weapons, as America, France, Israel, Russia?" The common denominator of both comments: confirmation of Israel's presumed nuclear capabilities. Olmert's statement - which violated Israel's policy of nuclear ambiguity - caused quite a stir in local diplomatic and defense circles. But he was not the first Israeli leader to make such a "slip of the tongue." In December 1974, president Ephraim Katzir said that Israel had "nuclear potential." In 1981, after the destruction of Iraq's Osirak reactor, former defense and foreign minister Moshe Dayan told The New York Times: "We do have the capacity to produce nuclear weapons." In 1998, at a press conference in Jordan, then foreign minister Shimon Peres said that Israel had "built a nuclear option, not in order to have a Hiroshima but an Oslo." (This was a veiled warning of the possible consequences to failed peace talks.) Ironically, it was Peres himself who, under prime minister Levi Eshkol, had formulated the ambiguity policy in the first place in the early 1960s. When Eshkol pledged that "Israel [would] not be the first nation to introduce nuclear weapons into the Middle East," he was neither admitting nor denying possession of such weapons. Yet, on two occasions, according to foreign reports - during the Six Day and Yom Kippur wars - the Israeli leadership, fearing the country's existence was in jeopardy, ordered nuclear bombs to be loaded onto attack jets for what has been dubbed "the Samson option." Since then, foreign reports have even gone so far as to report the location of Israel's Jericho 2 ballistic missiles. These missiles, according to Jane's Intelligence Review, have a range of 5,000 km. and are capable of carrying a 1,000-kg. warhead - enough for a nuclear weapon. Furthermore, according to Jane's, these missiles are kept at an air force base near Zachariah, where there are also several bunkers that hold nuclear gravity bombs for attack jets stationed at the nearby Tel Nof air force base. WITH ALL that information out there, what was it about Olmert's comment that caused such a ruckus? The timing. With Iran racing toward nuclear capability, Israeli officials have begun deliberating the continued importance and wisdom of nuclear ambiguity. Some have called for "nuclear transparency" - or at least for flexibility where "ambiguity" is concerned. This could come in the form of an official announcement on the part the government. Still, the general attitude of the defense establishment favors ambiguity. Olmert recently held two four-hour meetings with Dan Meridor - author of Israel's newly formulated defense doctrine - during which he was briefed on the value of retaining the long-standing ambiguity policy. Olmert has also held discussions with Ilan Mizrahi - head of the National Security Council and former deputy head of the Mossad - the outcome of which was a decision to uphold ambiguity. "This policy scares our adversaries," Mizrahi has said. BUT EVEN if he wanted to, senior defense officials said this week, Olmert would not be able to change the policy unilaterally - certainly not via German television. He would have to do it in conjunction with the Atomic Energy Commission and the Security Cabinet. These officials explained the value of having a gap between presumption and certainty, chief among them avoiding the scrutiny of the International Atomic Energy Agency, and providing effective deterrence in the face of its enemies. In addition, the policy has successfully warded off attempts by other Middle Eastern countries - with the exception of Iraq and Iran - to have an excuse to begin developing their own nuclear weapons. The US has implicitly endorsed Israel's ambiguity policy over the years, as it has allowed various administrations to stave off calls - such as those from Egypt - for international inspections of Israeli nuclear sites. The policy has also allowed Washington to continue giving billions of dollars of annual military aid to Israel - something that could come under major domestic and foreign attack if Israel were formally to let the cat out of the bag. Even more delicate - and crucial - considerations relate to what Gates delineated as Iran's excuse for developing a nuclear weapon: its desire to be like the rest of the region and Israel. If international diplomacy fails to stop Teheran, Israel may be left with no alternative but to take military action. A change in its nuclear policy would make it that much more difficult for Jerusalem to justify such action.