Nikolas Gvosdev makes a characteristically smart observation about the framework agreement with Iran:

The reality on Iran is that most of the other major powers were prepared to leave some degree of nuclear infrastructure in place, provided that it is closely supervised, and did not support the U.S. demand for complete abandonment. In addition, having agreed to accept much more stringent sanctions on Iran that limited vital flows of energy to their own markets, all at Washington’s request, key European and Asian allies are looking forward to a settlement that will get Iran’s considerable reserves back on the market. So the agreement reached in Switzerland is as much a compromise between the U.S. and the other major powers as it is with Iran [bold mine-DL].

One of the recurring criticisms of the framework agreement is that the U.S. has been willing to accept less than it was originally demanding a few years ago. This is normally portrayed by opponents of a nuclear deal as simply giving in to Iran for no reason, but it is useful to remember that the other governments involved in these negotiations didn’t share Washington’s maximalist goals on the nuclear issue. The U.S. has compromised with Iran on allowing some limited enrichment because Iran would never accept giving that up entirely, but it has also been forced to recognize that the other parties in the negotiations saw no need to insist on such harsh terms.

This should also make clear how limited and temporary international support for pressuring Iran on this issue will be in the absence of a final deal. The allies in Europe and Asia that are looking forward to getting back to doing business with Iran aren’t interested in pursuing our Iran hawks’ impossible goals at their expense, and they have cooperated as much as they have because they saw it as a way to settle the dispute. They aren’t going to keep cooperating at significant cost to themselves to make our hard-liners happy.

The option of walking away and increasing pressure that Iran hawks keep pushing as the alternative will be impossible once most other major nations resume their business with Iran. To pass up this opportunity to resolve the nuclear issue before that happens will mean blowing the best chance that the U.S. has to get Iran to agree to restrictions on its program. It will also mean squandering the last time when the U.S. will have this much international support for putting pressure on Iran.