The Iran nuclear agreement—characterized by The Washington Post’s editorial board as the “most consequential US diplomatic agreement in decades”—will go forward, as all but four Senate Democrats rallied to fend off Republican efforts to torpedo it. The difficult and concrete achievement of diplomatic compromise has overcome the vacuous fantasies of military bluster. The question now is: What comes next?

Led by the early support of presidential candidates Hillary Clinton, Senator Bernie Sanders (I-Vt.) and Martin O’Malley and pressured by grass-roots activists, Democrats in the House and Senate lined up to defend the agreement (with a notable exception of Senator Charles Schumer of New York, who aspires to lead the very caucus he abandoned).

But now, opponents and supporters threaten to hamstring it at birth. Instead of building on the agreement to explore new areas of cooperation, the administration and its critics are pivoting quickly to threatening Iran in anticipation of it cheating on the agreement. While the agreement calls for lifting multilateral sanctions focused on foreign companies, most US sanctions against Iran will remain in place. The administration and senators of both parties are now proposing new sanctions and military maneuvers to ratchet up the pressure on Iran. Not surprisingly, that has precipitated a harsh reaction from Supreme Leader Ayatollah Ali Khamenei. This could quickly snatch defeat from the hands of victory, foreclosing any broader transformation of US-Iranian relations and locking the United States into a continuation of its failed Middle East strategy.

Read the full text of Katrina’s column here.