GOP lawmakers who have declared their opposition to the nuclear deal with Iran have so far failed to articulate a detailed strategy for what would come next if they secure enough votes to derail the agreement. 

Republicans interviewed by CQ acknowledged it would be incredibly difficult to reconstitute the international sanctions regime on Tehran if lawmakers vote in veto-proof margins to override President Barack Obama’s promised veto of any resolution of disapproval.

“I’m afraid it’s a lost cause,” Sen. Ron Johnson, R-Wis., said last week. “I think once you lift these [international] sanctions, once everything starts flowing in, once investments start coming in from the West, you’ll never be able to stand up that coalition [again].”

The sanctions regime covering Iran is a complex knot of interwoven measures enacted over the years by the United States, the European Union and the U.N. Security Council. The sanctions target Iran’s oil and financial sectors in addition to its military, nuclear and missile development programs.

But it was the 2012 blacklisting of major Iranian banks from the global financial system by the United States and a European Union-wide oil embargo that are viewed to have finally driven the nation to the negotiating table. The willingness of countries such as Japan, China, South Korea and India to reduce their petroleum imports from Iran has also played a role.

Under the terms of the Iran deal, called the “Joint Comprehensive Plan of Action,” Tehran will not receive any sanctions relief until “Implementation Day,” the date on which the International Atomic Energy Agency certifies that Iran is in compliance with the initial set of nuclear restrictions under the agreement. At that time, under the terms of a Security Council resolution adopted last month, most U.N. and EU sanctions would be lifted as would some U.S. penalties. As it is expected to take Iran some months to implement the nuclear commitments, implementation day is not anticipated before early next year.

In the unlikely event enough Democrats defect and join with Republicans to override Obama’s promised veto, the immediate impact on the sanctions regime would likely be negligible, according to Blaise Misztal, director of national security at the Bipartisan Policy Center.

“Implementation day is not going to happen until well after Congress votes on the deal so the time at which sanctions have to be lifted is going to be several months later,” said Misztal, whose organization has not taken a stance on the deal.

If Iran responds to a successful veto override by immediately backing out of the multinational agreement, there is no legal mechanism in place for it to receive sanctions relief. However, the European Union, Russia, China, Japan and other nations may decide on their own that negotiating a stronger agreement is not possible and, given congressional intransigence on the issue, end their participation in some international sanctions such as the oil embargo.

“All of the testimony from people who know has been that they would fray if not unravel,” said Sen. Angus King, I-Maine.

But Misztal believes it is more likely Iran initially would abide by the deal.

“They can play the slightly longer game, make the initial nuclear concessions, get the certification by the IAEA triggering relief and then come back to the U.S. and say ‘Where is your sanctions relief,’ go through the dispute resolution process claiming the U.S. is noncompliant, which we would be if Congress rejects the deal,” he said. “And then Iran gets to both solidify the sanctions relief from the U.N. and EU and walk away from the deal so it would get the best of both worlds.”

GOP Lashes Out Over U.N. Action

Republican senators who spoke with CQ on Thursday mostly declined to directly respond to the above scenario and the question of whether partners such as India, Japan and the European Union would continue to participate in a U.S.-led sanctions regime.

Many preferred instead to accuse the White House of placing them in an intolerable position by not waiting for Congress to complete its review of the deal before supporting the July 20 adoption of a unanimous Security Council resolution that put in place the legal mechanisms for Iran to receive sanctions relief under the deal.

“I believe the president will be held accountable for going to the United Nations before coming to the Congress,” said Sen. John Barrasso, R-Wyo.

“I think it was the intention of the president to end-run Congress and shut off our voice,” said Sen. Cory Gardner, R-Colo. “That’s very much what his intentions were when he went to the United Nations.”

Added Sen. John Thune, R-S.D., “Obviously, it’s more difficult [to foresee maintaining international sanctions] now that we’re this far along in the process.”

Sen. Johnny Isakson said he was not thinking about how foreign countries would respond to a possible veto override.

“I can’t think beyond [congressional review] right now to what Russia may do or what the EU may do or the P-5+1,” the Georgia Republican said, referring to the group of five world powers that negotiated opposite Iran in the nuclear talks.

Anthony Cordesman, national security expert with the Center for Strategic and International Studies, said Republican criticisms of the U.N. action were unwarranted given that Obama was only exercising the authority given to him by congressionally enacted laws. He also was dubious that Europe would follow Congress’ lead in calling for a better deal if lawmakers managed to derail U.S. sanctions relief.

“There is no practical chance that you are going to see the Europeans support the U.S. on the basis of a congressional vote,” he said, noting that since the deal’s announcement senior French and other European officials have traveled to Iran to explore establishing deeper economic ties there. “The reality is that essentially we will end up almost certainly trying at best to enforce sanctions unilaterally on a world that is not prepared to follow us and which can take its own countermeasures and retribution.”