"If the President does not certify Iranian compliance, the Corker-Cardin law also tells us what happens next. What happens next is significantly in Congress's hands," Haley said.
"This is critically important, and almost completely overlooked. If the President chooses not to certify Iranian compliance, that does not mean the United States is withdrawing from the [deal]."
She was referring to the Iran Nuclear Agreement Review Act, which Congress passed after the Obama Administration and the other P5+1 countries agreed to the Joint Comprehensive Plan of Action (JCPOA) with Iran.
The law sets the requirement that Trump certify Iran's compliance every 90 days. If Trump does not certify Iran's compliance, the law provides for an expedited process whereby Congress could reimpose the sanctions lifted under the agreement - or do nothing at all.
Haley's remarks represent the highest-level acknowledgment that the Trump Administration might choose to declare the deal broken, while leaving the sanctions issue and the future of the agreement for Congress to deal with.
During the question-and-answer section of Haley's event, the New York Times's Gardiner Harris said that Congress, including Republican allies of the Administration, does not want to add a debate over the Iran deal to its already crowded autumn legislative calendar and asked Haley why the Administration would abdicate ultimate responsibility for deciding the deal's fate.
"Why this middle path where you decertify and force Congress to make this hard decision for you, rather than make this hard decision yourself?" he asked.
Haley responded that the Administration is not trying to sidestep its responsibility; it is simply following the law.
"I get that Congress doesn't want this. This is not an easy situation for anyone," she said. "But our lives are not about being easy, our lives are about being right."
If Trump follows that course, it would signal "one or more of the following three messages to Congress," Haley said. The Administration believes Iran is in violation of the deal; or the lifting of sanctions against Iran is not appropriate and proportional to the regime's behaviour; or the lifting of sanctions is not in the US national security interest.
Congress would have 60 days to consider whether to reimpose sanctions or conclude that the Iran deal is "too big to fail," said Haley. Congress could also debate Iran's support for terrorism, its past nuclear activity and its human rights violations, she added.
Experts are already debating what Congress should do if Trump declines to certify Iranian compliance with the nuclear deal. One approach, advocated by Mark Dubowitz of the Foundation for the Defence of Democracies and David Albright of the Institute for Science and International Security, argues Congress should drastically increase non-nuclear sanctions on Iran but stop short of reimposing the sanctions that would blow up the deal.
Congressional leaders have not revealed their thinking publicly. New sanctions would need 60 votes in the Senate, and key Democrats who opposed the nuclear deal, such as Senator Charles Schumer, have not said whether they would vote for action that could destroy the Iran accord.
Haley said she has not had any discussions with leaders in Congress about what might happen after Trump fails to certify Iranian compliance. She acknowledged that European allies want the deal to continue but also pointed them to Congress for guidance.
"Because the European allies understand the concerns we have with Iran, if they saw the President decertify, they would realise this is going to Congress and they would watch that debate very closely," she said.
As with Deferred Action for Childhood Arrivals, punting the Iran issue to Congress seems like a way for the Trump Administration to have its cake and eat it too, by declaring Iran non-compliant but not taking responsibility if the deal subsequently falls apart.
But if Trump pursues that strategy, the result will likely be similar to what we are seeing with DACA: confusion, uncertainty about the path forward and the risk that congressional inaction could have drastic unintended consequences.
