President Obama made a statement Saturday night from the White House.  WASHINGTON â The interim accord struck with Iran on Sunday interrupts the countryâs nuclear progress for the first time in nearly a decade, but requires Iran to make only a modest down payment on the central problem.  The deal does not roll back the vast majority of the advances Iran has made in the past five years, which have drastically shortened what nuclear experts call its âdash timeâ to a bomb â the minimum time it would take to build a weapon if Iranâs supreme leader or military decided to pursue that path.  Lengthening that period, so that the United States and its allies would have time to react, is the ultimate goal of President Obamaâs negotiating team. It is also a major source of friction between the White House and two allies, Israel and Saudi Arabia, which have made no secret of their belief that they are being sold down the river.  Prime Minister Benjamin Netanyahu of Israel has described the terms of the accord announced early Sunday as a âbad dealâ that does not require Iran âto take apart even one centrifuge.â That bitter assessment reflects the deep suspicion inside Mr. Netanyahuâs government that Mr. Obama will settle for a final agreement that leaves Iran a few screwdriver turns short of a weapon.  The Saudis have been equally blistering, hinting in vague asides that if the United States cannot roll back the Iranian program, it may be time for Saudi Arabia to move to Plan B â nuclear weapons of its own, presumably obtained from Pakistan, which entered the nuclear club on Saudi subsidies.  Such warnings are part of the expected theater of these negotiations, in which the United States must look simultaneously accommodating enough to a new Iranian leadership to keep fragile talks going and tough enough to its allies and Congress that it cannot be accused of naÃ¯vetÃ©. That is why Mr. Obama, speaking at the White House late Saturday, called the interim deal a necessary first step.  Iranâs agreement to convert or dilute the fuel stocks that are closest to weapons grade, Mr. Obama said, means that the deal would âcut off Iranâs most likely paths to a bomb.â But it would cut them off only temporarily, long enough to pursue negotiations without fear that Iran would use the time to inch closer to a weapons capability.  But the rollback he won for this first stage, according to American intelligence estimates, would slow Iranâs dash time by only a month to a few months.  The most immediate risk to the interim agreement comes from hard-liners in Washington and Tehran who, after examining the details, may try to undo it. Mr. Obama met with senators from both parties last week, hoping to dissuade them from imposing new sanctions just as he is lifting some in an effort to coax Iran toward disarmament. But even some of his closest allies are unconvinced: Senator Charles E. Schumer, Democrat of New York, signed a letter to Secretary of State John Kerry last week noting that the temporary accord âwould not require Iran to even meet the terms of prior United Nations Security Council resolutions,â which require complete suspension of nuclear production.  On the Iranian side, the Islamic Revolutionary Guards Corps, which American intelligence agencies have accused of running a secret weapons-design program, may try to chip away at the accord as well, arguing that the sanctions relief is puny and that even the caps on enrichment will slow Iranâs efforts to build its nuclear capabilities.  Mr. Kerry and his chief negotiator, Wendy Sherman, say they have no illusions that the interim agreement solves the Iranian nuclear problem. It simply creates time and space for the real negotiations, they say, where the goal will be to convince Iranian leaders that the only way to get the most crippling sanctions â those that have cut the countryâs oil revenue in half â lifted is to dismantle large parts of a program on which they have spent billions of dollars and staked national pride.  âRollback may be a step too far for the Iranians,â said Vali R. Nasr, the dean of the School of Advanced International Studies at Johns Hopkins University. Iranâs recently elected president, Hassan Rouhani, âcanât go there for some time,â Dr. Nasr said, âbecause he canât been seen at home giving up such a huge investment or abandoning national security.â  Lurking over the American negotiating team is the specter of what can go wrong even with a seemingly good deal to buy time. As Ms. Sherman was coaxing Iranâs foreign minister, Mohammad Javad Zarif, toward the interim agreement, the North Koreans were restarting a nuclear reactor that they had partly dismantled in a similar agreement struck late in the administration of President George W. Bush â a deal meant to halt North Koreaâs ability to produce plutonium fuel for weapons.  âIt lasted five years, which isnât bad,â said Christopher R. Hill, who conducted the North Korean negotiations for the Bush administration and is now dean of the Josef Korbel School of International Studies at the University of Denver. âBut the reality is that, over time, everything is reversible.â  The North Korean example has become Exhibit No. 1 in Israelâs argument that the deal struck on Sunday gives a false sense of security. âThere are two models for a deal: Libya and North Korea,â Israelâs minister of strategic affairs and intelligence, Yuval Steinitz, said in an interview during a recent trip to Washington. âWe need Libya.â  Mr. Steinitz was referring to a 2003 agreement in which Libya gave up all of its nuclear equipment and was left with no ability to make nuclear fuel. But Libya had barely managed to unpack its equipment, purchased from Pakistan; it had invested far less than Iran and was nowhere near enriching nuclear fuel. In reality, no one imagines the Iranians will give up everything. The question is, how much is enough?  The complexity of the task ahead is evident from a glance at the main measurements of Iranâs progress since Mr. Obama took office in 2009, promising a new opening to the Iranians â an opening they had largely rejected until this summer, when the mounting toll of economic sanctions helped Mr. Rouhani win the presidential election.  This article has been revised to reflect the following correction:  An earlier version of this article misidentified the title of Yuval Steinitz. He is Israelâs minister of strategic affairs and intelligence, not its defense minister.
The interim deal brings the Obama administration a step closer to its ultimate goal: lengthening the time it takes Iran to build a weapon.