It’s a strong deal and Congress should stand behind it. We know that the alternatives look grim. As former National Security Council official Philip Gordon has pointed out, if this deal is rejected, Iran’s nuclear program will be unconstrained: “Kill that deal, and tomorrow Iran can resume enrichment including to higher levels, keep its fissile material stockpile, finish building its heavy water reactor and do unlimited R&D, all without transparency or international supervision.”

It should be noted that this agreement does not only belong to the United States or Iran, but to the entire international community. If Congress moves unilaterally to reject this deal and the herculean efforts of our allies, it would be seen as extraordinarily provocative. It would embolden Iranian hardliners who exploit the widespread perception in Iran that the United States is a dominating, capricious aggressor who turns away at the opportunity to engage in dialogue.

Rejecting this landmark agreement would be a flagrant rejection of the tremendous progress our diplomats and our allies have made to rein in Iran’s nuclear program, and the leadership our country has shown on the international stage.