A war-weary Congress generally backs President Barack Obama's outreach to Iran, but with tougher U.S. economic measures against Tehran on the way, the president's diplomatic task could get harder if he doesn't make quick progress.
Obama's phone call last week to Iranian President Hassan Rouhani was a groundbreaking conversation. It was the first contact in more than 30 years between the leaders of the two countries and an about-face from when Obama's predecessor, George W. Bush, included Iran in his "axis of evil" with North Korea and Iraq.
The sentiment in Washington's political circles has changed, too.
During the current shutdown, "people are continuing to move the process along and so when the government is back open for business I would expect the bill to come out of the Senate Banking Committee and get to the next stage of the legislative process," said Mark Dubowitz, executive director of the Foundation for Defense of Democracies, a Washington-based think tank that advocates for a tough line on Iran.
Debate on Capitol Hill about Syria also has changed the dynamic on U.S. ties with Iran.
Lawmakers were reluctant to keep a U.S. military option on the table in connection with the crisis in Syria after the Aug. 21 chemical weapons attack outside Damascus, which, according to administration estimates, killed more than 1,400 people. It's difficult to see how Congress would support a U.S. military strike on Iran over its nuclear program, and that might strengthen Obama's case for a diplomatic resolution to the standoff.
Sen. Mark Kirk, R-Ill., a member of the Senate Banking Committee, is in favor of a tough new round of sanctions.
"We should judge Iranian leaders by their actions, not their words," Kirk said Tuesday. "So long as Iran continues to pursue a nuclear weapons capability, build longer-range ballistic missiles, sponsor terrorism around the world and abuse human rights, the Senate should impose maximum economic pressure on Iran to give diplomacy a chance to succeed."
On Monday, Sen. Bob Menendez, D-N.J., chairman of the Senate Foreign Relations Committee, said he welcomed diplomatic engagement with Iran, but said it "cannot be used to buy time, avoid sanctions and continue the march toward nuclear weapons capability."
In the House, Rep. Adam Schiff, D-Calif., said Obama's engagement with Rouhani "holds the promise, albeit tenuous, distant and difficult, of a resolution of the Iranian nuclear question." Writing off chances for success without trying would be "negligent," he said.
Meanwhile, Republican Rep. Ed Royce, R-Calif., the House Foreign Affairs Committee chairman, credited America's "damaging sanctions" for getting Rouhani on the phone and said the U.S. must increase economic pressure "until Iran stops its nuclear drive."
Some Iran experts, such as Trita Parsi, president of the National Iranian American Council in Washington, believe that any new sanctions imposed at this time will destroy the prospects of diplomacy. Dubowitz believes, however, that the Obama administration would be OK with Congress passing new sanctions as long as it's not too soon.
"If the sanctions are on the president's desk by tomorrow morning, I think they would probably face quite a bit of resistance from the White House right now in terms of timing and atmospherics," Dubowitz said. "But I think the White House appreciates that it's very useful to have Congress move the sanctions bills through the process at the same time as the U.S. is engaging Iran on the diplomatic side."