Forty years ago a flustered Shimon Peres faced off with US president John F. Kennedy on a secret seen as critical to the Jewish state's survival, and got away with saying next to nothing.
"Kennedy began bombarding me with questions. Suddenly he says, `Are you making an atom bomb?' I told him, `Mr President, I can promise you one thing: Israel will not be the first to introduce nuclear weapons into the Middle East,'" Peres recalled in the recent documentary film A Bomb in the Basement.
That sidestep by Israel's veteran statesman evolved into a strategy of ambiguity straddling two national needs -- to strike fear into numerically superior foes while calming global jitters at any doomsday saber-rattling in the volatile Middle East.
"We chose uncertainty, which afforded deterrence as far as the Arabs were concerned and convenience as far as our friends were concerned," Peres said.
Critics insist the policy -- enforced at home by military censors and abroad by agents who, in one case, abducted an Israeli whistle-blower -- is counterproductive, breeding speculation that it could spur a regional arms race.
The director of a Washington-based watchdog group likened Israel's "opacity" to that of the Soviet Union in the Cold War, saying this hastened US nuclear programs and increased tensions.
"As it turned out, the Soviets were not so well stocked," said Daryl Kimball of the Arms Control Association. "Ever since, it has been proven that greater knowledge about different nations' nuclear weapons generally leads to greater responsibility."
Daniel Seaman, director of the Israeli government press office, who liaises between the media and the security services, disagrees.
"Israel won't discuss non-conventional capabilities, but it wants to keep the enemy guessing," he said. "Ambiguity is not all about denial. Speculation also makes for deterrence."
Israel did not sign the 1970 UN Treaty on the Non-Proliferation of Nuclear Weapons and thus kept its main reactor, in the desert town of Dimona, exempt from inspections.
At least 200 nuclear warheads are believed to have been produced at Dimona, an estimate based on disclosures by nuclear technician Mordechai Vanunu to Britain's Sunday Times newspaper in 1986 and other exposes quoting unnamed intelligence sources.
Last month, as international calls for the inspection of Iran's atomic reactors mounted, the Los Angeles Times reported that Israel had extended its reach to the Islamic republic by arming US-made, submarine-launched missiles with nuclear warheads. The newspaper cited US administration sources and -- in the first such claim by a reputable publication -- said an Israeli "official" confirmed the missile had been modified.
The Pentagon and the Israeli government declined to comment. Duncan Lennox, editor of Jane's Strategic Weapons Systems, said the report's timing was no less important than its truthfulness.
"Iran must be very worrying to Israel. Hence I would think that the stories of Israel's capabilities may be aimed at saying to Iran, `You may get some nuclear weapons, but there will always be retaliation if you attack first,'" Lennox said.
Such theories sit well with Israeli journalists like Michael Karpin, whose A Bomb in the Basement enjoyed unprecedented access to the nation's atomic architects and privileged files.