Claim That Iran Sanctions Are Like a Spigot Doesn't Hold Water Under Questioning of Treasury Official

Any acceptable deal "must require Iran to dismantle large portions of its nuclear infrastructure. Any final deal must address Iran's advanced centrifuge research and development activities that allow it to more quickly and more efficiently enrich uranium. It must eliminate the vast majority of Iran's 20,000 centrifuges, close the Fordow facility, and stop the heavy water reactor at Arak from ever coming online. And it must address Iran's weaponization activities at Parchin and possibly elsewhere, something not directly dealt with by the joint plan of action…. A final agreement should move back the timeline for breakout to beyond a year or more, and insist on a long-term, 20-year-plus regime of monitoring and verification."

"A final agreement that mothballs Iran's infrastructure, or fundamentally preserves their ability to easily break out, is not a final agreement I can support," Menendez added.

Ranking Member Bob Corker (R-Tenn.) revived a legislative possibility raised by Menendez at a previous hearing, in which Congress would try to exert a stronger say over the final agreement.

"Maybe what Congress should do is pass a piece of legislation that lays out clearly the only thing we will accept at the end," Corker said, highlighting the fear of many in Congress that the administration will just forge a series of never-ending rolling agreements.

Sherman claimed that, on the stated desire to keep Iran from obtaining a nuclear weapon, "I am certain that we are closer today to that goal than we were just a few weeks ago."

"The P5+1's negotiations with Iran underscores that it is possible not only to make progress on the nuclear issue, but with Iran," she said. "The coming months will be a test of Iran's intentions of the possibility of a peaceful resolution to the crisis."

When Menendez asked for a yes-or-no answer on whether a final agreement would close Fordow, Sherman responded, "In all of these questions today, I'm going to be thoughtful about what I say, Senator, not because I do not want to be direct, but I don't want to negotiate with Iran in public so that they know what our positions are going to be at the negotiating table. So I will be as forthcoming as I can be."

She brushed off his question about the number of centrifuges Iran would need to remove and called President Hassan Rouhani's claim that the agreement won't call for any destruction of centrifuges "an opening maximalist negotiating position."

Menendez noted another big flaw in the interim agreement: no access to Parchin, the military complex near Tehran believed to be ground zero for Iran's nuclear weapons program.

"In the interim, in your joint plan of action, they rejected, during this period of time, access to it," he said.

Sherman said it hadn't been rejected, it just needed to be addressed. "I hope and I would urge Iran to address Parchin during these six months while we are negotiating the comprehensive agreement because it will increase the confidence that we will actually get to a final and comprehensive resolution," she said.