On Iran, 2 Central Questions Divide U.S. and Israel WASHINGTON - Despite the upbeat characterizations of their talks at the White House on Monday, President Obama and Prime Minister Benjamin Netanyahu of Israel remain divided on two central questions about Iran's nuclear program: If Iran decided to race for a nuclear weapon, would the West detect it in time to stop it? And even if it was detected, is an air strike the best option? From the top ranks of the administration down, American officials say they would almost certainly detect a sprint to manufacture a weapon - though even inside the United States government there have been doubters on that subject, notably the former secretary of defense, Robert M. Gates. The Israelis say it might be detectable, but it might not. And, they say, that everything from the history of the Holocaust to the tight geography of the Middle East demands that they assess the risk of missing the turn in Iran much more critically than Washington. "Amazingly, some people refuse to acknowledge that Iran's goal is to develop nuclear weapons," Mr. Netanyahu said on Monday evening in a speech to the American Israel Public Affairs Committee, the hawkish, pro-Israel lobbying group, dismissing the American arguments that Iran may only been seeking the option to build the ultimate weapon. You see, Iran claims that it's enriching uranium to develop medical research. Yeah, right. Mr. Netanyahu went on to make an explicit reference to the Holocaust, reading from a 1944 letter from the American War Department to the World Jewish Congress rejecting a plea to bomb Auschwitz before declaring: "My friends, 2012 is not 1944. The American government today is different. It's different. In meetings with Mr. Obama's top national security advisers in recent weeks, Mr. Netanyahu has been cagey about defining when Iran will - by Israel's definition of the problem - get so close to a nuclear capability that he will judge a military strike as the only available option. "He clearly has not made a decision," one official who met him recently said as Mr. Netanyahu was arriving in Washington. And I'm not sure he'll tell us when he does. Instead, Mr. Netanyahu has been warning against getting involved in negotiations with the Iranians that he believes Tehran could use to deflect the growing pressure and to make it far harder for Israel to threaten a military attack. Speaking in Canada before he arrived in Washington, Mr. Netanyahu demanded that before any negotiations with Iran resume, Iran must take a set of steps that would preclude it from taking the next steps toward a bomb. Those would include halting the production of new nuclear materials, dismantling the deep-underground enrichment plant at Qom that the Israelis fear their bunker-busters cannot reach, and shipping most of its stockpile nuclear fuel - enough to produce about four weapons, if it was further enriched - out of the country. Mr. Obama's advisers say the chances of the Iranians agreeing to those steps at the outset of a negotiation are zero. The American response is that the United States and its European allies have the time to try another round of negotiations, and in fact, the United States and five other nations said on Tuesday that they had accepted an Iranian offer to resume negotiations. "I have zero doubt that if Iran attempted a breakout, we'd see it," one senior administration official said several weeks ago, referring to any effort by Iran to disregard the Nuclear Nonproliferation Treaty and turn reactor-grade fuel into bomb-grade fuel. Intelligence officials say they believe they would see the signs: Inspectors would likely be barred from the country or key facilities, and the West's contacts inside the Iranian scientific community would likely report a change in the actions of the laboratories run by Mohsen Fakhrizadeh, the Iranian believed to be leading the weaponization program. But in the past, there have been doubts. Two years ago, Mr. Gates, on "Meet the Press," asked: "If their policy is to go to the threshold but not assemble a nuclear weapon, how do you tell that they have not assembled? I don't actually know how you would verify that. The truth is that the answer to the question is unknowable. While American intelligence agencies famously misjudged that Saddam Hussein was advancing on a bomb project when he had none, they also have a long record of missing signs that countries were getting very close to a bomb. They missed the timing of the first Soviet nuclear test in 1949 - to President Harry Truman's outrage - and got the timing wrong on the Chinese in the 1960s, the Indians in the "70s, and the Pakistanis in the "80s. To this day, even after North Korea conducted two nuclear tests, no one is quite sure whether the country's engineers actually know how to make and deliver a real, working bomb.