The pros and cons of the accord with Iran over its nuclear program will be debated extensively over the next two months, in the run-up to a vote on the deal by the U.S. Congress. But the so-called Joint Comprehensive Plan of Action will be judged by its implementation, which will take years.

Nonetheless, two things are already clear. First, the JCPOA's weakest provisions — both cumbersome and open to competing interpretations — are those covering compliance and verification. So some skepticism about implementation is in order.

Second, and more immediately, the very achievement of an agreement between Iran and the five permanent members of the U.N. Security Council plus Germany (the P5+1) has already begun to affect the regional balance of power. Indeed, it is legitimate to ask whether Western (and especially U.S.) negotiators were aware of the geopolitical implications of the deal.