“We need to know what we will do in advance, and that includes potentially striking (Iran) in their homeland,” said James Jeffrey, Visiting Fellow at the Washington Institute for Near East Policy, testifying on U.S. policy towards Iran at a House Foreign Affairs Committee hearing last week. Jeffrey was supportive of a policy of pushing back against Iran’s non-nuclear activities, though acknowledged that Iran typically responds to escalation with escalation, hence his recommendation of being ready to strike Iran on its own territory.

Critics of the accord were out in force at the hearing ahead of Trump’s decision to refuse to certify the agreement, but many lawmakers are so far not having it.

“I think we should wait and see what President Trump says but I think we could rewrite the conditions of the deal,” argued David Albright, a major critic of the Iran deal from the Institute for Science and International Security.

“You think the Congress of the United States has the ability to unilaterally change the terms or meaning of terms in an international agreement?” responded Rep. David Cicilline (D-RI) to Albright. “You don’t need to answer that question. The answer is of course not.”

With opponents of the nuclear deal wavering on snapping back sanctions to kill the accord unilaterally, the Trump administration and opponents of the accord are now urging that Congress pass legislation to effectively issue an ultimatum to Iran, as well as Europe and the other parties to the agreement, to amend the deal.

However, even Congressional opponents of the deal appear inclined to stick with it. “As flawed as the deal was, I believe we must enforce the hell out of it,” began Chairman Ed Royce (R-CA) in his opening statement, effectively opposing a unilateral snapback of nuclear sanctions following Trump’s expected certification.

“Let’s work with allies to make certain that international inspectors have better access to nuclear sites, and we should address the fundamental sunset shortcoming as our allies have recognized,” said Royce (R-CA), who is also championing new non-nuclear Iran sanctions legislation as an alternative to snapping back nuclear sanctions.

However, Royce appeared open to efforts to renegotiate the accord, echoing the powerful pro-Israel lobby AIPAC that opposes the Iran deal and is lobbying Congress to eliminate sunsets in the agreement. Many observers view “renegotiation” as another means to violate and terminate the accord.

Jake Sullivan, a former nuclear negotiator and policy adviser to the Hillary Clinton campaign, warned that an attempt to unilaterally rewrite the terms of the deal could lead to a collapse of the deal. According to Sullivan, if “he (Trump) decides, as I think as some have suggested, I’m just gonna unilaterally rewrite the terms of the deal myself and I think that would be a way, a sure way to end up collapsing the deal over time, without the rest of the world joining us and then re-imposing pressure.”

Rep. Ted Deutch (D-FL), who originally opposed the deal, warned against pulling out and collapsing the deal. “If we walked away from the agreement tomorrow, if the president pulled us out of the JCPOA, those sunsets would effectively drop from a decade to a day.” Such a move would leave the U.S. with two nuclear crisis on its hands, both Iran and North Korea, Deutch said.

The panelist Charles Wald, former U.S. Air Force general and co-chair of The Gemunder Center Iran Task Force suggested that, despite IAEA reporting indicating that Iran is complying with its commitments, he was certain Iran was in violation. “I would be 99.9% sure Iran’s cheating on the deal,” said Wald, claiming that the IAEA is not allowed into Iran’s military sites.

Rep. Greg Meeks (D-NY) pointed out the lack of evidence, saying that Wald’s statement “is  99% pure speculation and speculation without fact sir, is very dangerous.”

Sullivan rebutted Wald’s claims, noting that the JCPOA explicitly states that if the IAEA has reason to believe that there is illicit nuclear activity at any site in Iran, they must be allowed access. Sullivan said he had no reason to believe from the time that the JCPOA was instated that the IAEA could not gain access to military sites. “In the last two years, the United States actually hasn’t gone to the IAEA and presented a particular military site and said ‘I want to get access to that.’”