Philip Gordon explains  why there will be no renegotiation of the nuclear deal:
There is virtually no chance the other parties to the Joint Comprehensive Plan of Action would agree to insist on such changes (even under the threat of U.S. “secondary sanctions”) and virtually no chance Iran would agree to the changes even if new talks somehow took place. Instead of a new and better agreement, we would quickly be back to a place where Iran was advancing toward a potential nuclear weapons capability, and the United States had to decide whether to accept it or prevent it with military force — this time with virtually no international support and while dealing with an urgent nuclear crisis in North Korea at the same time.
Iran hawks have claimed to be interested in a “better” deal with Iran for years, but this has always been a ruse designed to obscure their reflexive hostility to all real engagement with Iran. Once there was the prospect of a compromise that would succeed in restricting Iran’s nuclear program starting in 2013, they were adamantly against the compromise. They insisted on maximalist demands that were never going to be accepted by the other side, and condemned anything short of their maximalism as “appeasement.” Four years later, Iran hawks want to make the same demands that Iran will never accept, but now they want to do it without any of the international support that the U.S. had during the original negotiations. Despite having less leverage today than the U.S. had before and virtually no international backing for their new scheme, they imagine that they can extract larger concessions from an Iran that is already complying with the existing terms. That obviously won’t succeed, but then it isn’t really meant to. Just by making the attempt, Iran hawks would jeopardize the hard-won gains that have already been made. Sabotaging the deal and sowing discord are the real goals of Iran hawks, and there should be no illusions about that.