BEIRUT -- A long-awaited preliminary nuclear agreement with Iran will take effect in one week, on Jan. 20, the White House announced Sunday.
The announcement, which was the product of weeks of technical negotiations following an earlier diplomatic breakthrough, is a hard-fought, if limited, victory for the president, who would like to see Iran's nuclear program dismantled through diplomatic means, instead of by force.
According to the terms of the final negotiations, the new agreement is a six-month temporary truce in which Iran agrees to reduce its stores of enriched nuclear materials and open its nuclear program up to greater scrutiny. In exchange Iran will get relief from certain debilitating financial sanctions.
"For the first time in almost a decade, Iran's nuclear program will not be able to advance, and parts of it will be rolled back, while we start negotiating a comprehensive agreement to address the international community's concerns about Iran's program," President Barack Obama said in a statement.
The American side of the deal -- a temporary lessening of certain financial restrictions imposed on Iran -- has been a topic of controversy in Washington in recent weeks, as several lawmakers have lent support to a bill that would impose new sanctions on Iran, outside of the terms of the deal announced on Sunday.
Lawmakers who support the sanctions bill, sponsored chiefly by Sen. Bob Menendez (D-N.J.), have insisted that they do not intend to interfere with the president's diplomatic efforts -- rather to bolster them by adding additional inducements for Iran to stick to the plan.
The White House has derided the legislative push as effectively an effort to derail talks and consequently push the U.S. closer to war with Iran. In his statement Sunday, Obama repeated his threat to veto any such bill.
"I have no illusions about how hard it will be to achieve this objective, but for the sake of our national security and the peace and security of the world, now is the time to give diplomacy a chance to succeed," he said.
A senior Senate Democratic aide told The Huffington Post on Sunday that despite the expectations of the bill's sponsors, it has little chance of coming to a vote in the near future.
"Ain't coming to the floor any time soon," the aide said.
Still, in a briefing for reporters on Sunday, several senior administration officials seemed sensitive to the arguments being made by the bill's supporters, and repeatedly emphasized that relief from the sanctions would be "modest" and temporary.
The deal would include "limited, temporary targeted and, critically, reversible relief," one official said. "If Iran fails to meet its commitments, we will move to not only cancel sanctions relief but will increase our sanctions."
Among the financial incentives being offered -- most of which had been announced during an earlier diplomatic session in Geneva in November -- are provisions that would reduce western challenges to Iran's oil sales to select countries, would permit humanitarian aid into the country, and would allow Iran to buy critical parts for its civilian airplanes.
In return, Iran will begin a process of converting all of its highly enriched uranium -- which, while not weapons grade, is currently at a level sufficient to be converted quickly into a weapon -- to a diluted form, and will open all of its nuclear facilities to more frequent inspections by the International Atomic Energy Agency.
Colin Kahl, a former senior Pentagon official in charge of Middle Eastern affairs, told HuffPost on Sunday that the deal offers the "first concrete step to put meaningful and verifiable constraints on Iran's nuclear program in more than a decade."
Any efforts by Congress to impose new sanctions or otherwise meddle with the plan would be a mistake, he added.
"Even if the likelihood of blowing up talks on a comprehensive agreement to peacefully resolve the nuclear impasse are low, as proponents claim, there is simply no advantage to threatening new sanctions at this delicate time -- only risk," he said.
"Congress has a key role to play -- but for now, the safest and smartest move would be to keep its powder dry on sanctions."
Trita Parsi, the president of the National Iranian American Council, hailed Sunday's announcement as a potentially monumental step for world peace.
"The decision to start implementation of the November nuclear accord shows that diplomacy is gaining further momentum," Parsi said. "Confrontation has been replaced with collaboration. If this process continues uninterrupted, the nuclear issue can be fully resolved, which significantly adds to U.S. national security."