Sealing a deal to keep Iran from becoming a nuclear power has gotten more complicated now that Congress has muscled its way onto the field of play. Allowing Congress 30 days to vote on a deal before any sanctions it previously imposed on Iran can be lifted could disrupt a nuclear agreement. But that's a risk worth taking.
The stakes are high. Congress should be involved in determining whether the United States and its partners -- Britain, France, China, Russia and Germany -- got the best terms possible. But lawmakers should play that role responsibly. They should avoid a replay of the nastiness and partisanship that led to an invitation for Israeli Prime Minister Benjamin Netanyahu to speak before Congress, and the sending of an open letter to Iran's leaders challenging President Barack Obama's ability to sustain a deal.
There are encouraging signs the congressional review will have a more bipartisan flavor.
Democrats, including minority-leader-in-waiting Sen. Charles Schumer of New York, joined Republicans in pushing for legislation that would give Congress a role in reviewing the agreement. The Senate Foreign Relations Committee crafted the bill in a give-and-take with Obama. The bill is now headed to the full Senate. And after initially resisting congressional involvement, Obama said he will sign it.
The bill would authorize Congress to vote on an eventual end to sanctions and then return to the issue later, allowing time to see whether Iran meets its obligations. Congress could also reject the agreement, a decision Obama could veto, which would require two-thirds majorities in the Senate and House to override. That means Democrats would have to join Republicans to ultimately block a deal.
With a June 30 deadline for a final pact looming over negotiators when they go back to the table this week, reaching agreement on the details won't be easy, particularly with Iran now agitating for sanctions to be lifted immediately and resisting inspections at its military bases.
Fortunately, there is now a chance the deal eventually reached will get a fair review from Congress.