John Kerry actually said...

this agreement gives us a chance to prevent an Iranian nuclear weapon through diplomacy and negotiations, rather than through war.

The overall effectiveness of the agreement will thus require the Obama administration and its successors to maintain a very tough inspection...

On balance, however, I believe the nuclear deal will deliver more advantages than disadvantages to the United States.

A vote of disapproval in the absence of a credible alternative, would, after 10 years of effort, be self-defeating for our country.