NEW YORK – For two great foreign policy struggles, 2014 just might be the year of the close.The US leads the international community into a new year prepared to hit the pause button on its long-standing nuclear crisis with Iran – and with a rare timeline promising closure, in one form or another, by year’s end.Three decades of tensions between Tehran and Washington began to thaw over the autumn months, precipitated not by goodwill but by the fear of limited alternatives. After 10 years of steadfast progress toward nuclear weapons capability, Iran has expanded its uranium enrichment program from 164 centrifuges in 2003 to over 19,000 in 2013. Time has run out for dalliance; the US seeks hard talks in the final hours of a crisis.The deal reached in Geneva last month between Iran and the P5+1 – the US, UK, France, Russia, China and Germany – calls for six months of negotiations toward a final-status accord while those centrifuges effectively freeze activity. That timeline may extend to 12 months should all parties agree that an extension would be fruitful.The Obama administration has made clear that if talks fail, the White House would seek swift and punishing new sanctions against the Islamic Republic, but also that such an alternative approach against Iran, should diplomacy fail, would be tantamount to an acceptance of war footing.“War is the failure of diplomacy,” US Secretary of State John Kerry told a foreign policy forum in Washington on December 11.Two weeks later, US President Barack Obama told reporters: “Ironically, if we did not have this six-month period in which we’re testing whether we can get a comprehensive solution to this problem, they’d be advancing even further on their nuclear program.”“It is very important for us to test whether [diplomacy] is possible, not because it’s guaranteed, but because the alternative is possibly us having to engage in some sort of conflict to resolve the problem with all kinds of unintended consequences,” he told a news conference in Washington before departing the White House for Christmas. Governments seek maximum flexibility in all pursuits, but this US administration has chosen a different path. Two politicians at the end of their political careers, Kerry and Obama, have put accountable deadlines on two of the world’s most challenging diplomatic initiatives since the fall of the Soviet Union.Perhaps more convoluted, more challenging, and even less likely for success due to the disinterest of the parties involved is the second time-bound negotiations process put forth by the US: the Israeli-Palestinian conflict.Repeatedly, the State Department has said the administration seeks not an interim solution to the historic conflict but an agreement that definitively ends the impass e between Israel and the Palestinians. It seeks the founding of a State of Palestine and the recognition of the State of Israel by the entire Arab League.Talks began in July of this year with a deadline of April 2014 – an extendable timeline, chief Palestinian negotiator Saeb Erekat said last week, though the US will push for a summit within 12 months of the beginning of talks.Erekat has said he does not believe a final-status accord is possible within the time frame outlined by the US. But it is possible the parties could reach a framework agreement, he said. That might only entrench the crisis, depending on whether such a deal has any teeth.Realpolitik on Iran suggests the new American timeline is forced and sincere: this year will be decisive in the conflict, more so than before, because it must be. The science of the conflict requires it.No such momentum exists on the latter conflict, between Israel and Palestine, that would aid American diplomats. Prime Minister Binyamin Netanyahu does not seek absolution from those who prioritize it; the Israeli people are not focused on it.And yet, by orchestration from this White House, these two great challenges will reach historic inflection points in a matter of months.When those moments arrive, naturally or forced, this president will define his foreign policy legacy – and the trajectory of the region – for many years to come.