The interim agreement reached between Iran and six world powers is supposed to be the first step on a long path of international diplomacy. Yet the accord, which temporarily freezes Iran's nuclear program over the next six months, is already proving contentious with the Obama administration insisting on the deal's merits and congressional critics highlighting its concessions. House Speaker John Boehner (R-Ohio), for instance, urged that the agreement be met "with healthy skepticism," while Sen. Chuck Schumer (D-N.Y.) said that it "does not seem proportional."
If the White House wants talks to move toward a more comprehensive disarmament deal, it will need to make its case not just to allies in the region but also to a skeptical congressional audience — and soon. For the Iranians, a key component of a more permanent agreement is the rollback of sanctions, which fall to a U.S. Congress that has already been itching for further penalties. Diplomacy with Iran hinges not only on the Islamic Republic's compliance then but also Congress's buy-in.
It is ironic that U.S. policy toward Iran is becoming so divisive since beneath all the bluster and bombast, this has been one of the most bipartisan issues in a Capitol perennially divided against itself. The Obama administration would be wise to nurture this rare bipartisan unity as much as the international coalition it has assembled against Iran.