Does the new version of the bill giving Congress a vote on the Iran nuclear agreement — a bill which President Barack Obama has agreed to sign — shift the constitutional balance of power when it comes to foreign agreements? At first glance, it looks as if it might: Obama initially declared that he could make an executive agreement with Iran that evaded Congress. Now he has agreed to sign a law that gives Congress the chance to review the deal before it goes into effect and block it if there are enough votes to override a presidential veto. This looks like a restraint on the president's untrammeled executive power in foreign affairs.
On second glance, however, the bill seems to be more symbolic than practical. Even if the bill didn't exist, Congress could still have responded to any Iran deal by enacting a resolution condemning it and blocking its implementation. The president could then have vetoed the resolution — essentially the same result that would occur under the new bill. Given this reality, the bill would seem to leave intact the existing division of powers between Congress and the president.
Which view is correct? It's too soon to tell because the eventual constitutional impact depends how the politics play out. When it comes to the complex relationship between the president and Congress in foreign affairs, actual political practice has shaped constitutional reality for more than 200 years. The text of the Constitution says little, and the meaning of the Constitution has therefore been determined not by formal textual analysis but by long-established practice.
In some scenarios, the new bill may function as a powerful political tool for congressional condemnation of unwanted presidential action in foreign affairs — in which case it could turn into a meaningful practical check on future presidents facing congressional majorities from the other party. In other scenarios, the bill might turn out to have practically no effect on separation of powers, because Obama and future presidents might simply act as though Congress had done nothing at all.
Start with a scenario in which Obama indeed strikes a deal with Iran, and Congress actually votes to condemn the deal. To make things interesting, assume that opponents of the deal can't get enough Democrats join the Republicans to reach the supermajority that would override a presidential veto.
What would Obama do next? Much turns on the answer. If he bowed to congressional pressure, and allowed the vote in Congress to scotch the deal, then we would be entitled to conclude that the current bill had a significant impact on the negotiation. Congress would have created a crucial opportunity for an automatic and formal review process — and would have exercised it. Future Congresses would try to do the same thing when they wanted to interfere with executive agreements reached by other presidents.
If, as seems more likely, Obama vetoed Congress' formal objection, then the scenario would probably turn out differently. Republicans would no doubt make the public point that the president shouldn't act against a majority in Congress, because doing so seems undemocratic.
But the Republicans' argument against the Iran deal might actually then be weaker than it would've been without the bill. The president would probably say in his veto message that he was simply following the script mandated by the bill. He had democratically given Congress the chance to review the deal, and Congress did so. There was a way for Congress to block the deal, namely a supermajority. Obama could therefore credibly say that Congress had in effect approved the deal by declining to block it via a supermajority.
Notice the remarkable fact that in this scenario, the current bill would have made the president, not Congress, stronger in the field of negotiating international agreements. The bill gives the president the chance to say that Congress has a role in reviewing the Iran deal, without strengthening that role in practical terms.
Behold the fascinating and weirdly uncertain effects of the present bill. Congressional Republicans seem to believe that by passing it, they are weakening the president and the Iran deal, because there will now be a formal chance for them to review and vote against it. Congressional Democrats, for their part, see an opportunity to please pro-Israel constituents or others who oppose the Iran deal — without blocking the president who comes from their own party from actually doing a deal.
As for Obama, he's more than smart enough to have thought of how the bill may actually strengthen him in the long run. He appears now to have made a concession to Congress by giving them a voice. But if he wants to override a later veto, he can say he hasn't acted undemocratically, even while going against a majority in Congress.
It isn't exactly true that everybody wins. But all sides might well be gambling credibly that the deal will help them more than it hurts. And that, let's recall, is the nature of a compromise.
Noah Feldman is a professor of constitutional and international law at Harvard University.