-——(you)keep Iran from advancing its nuclear weapons program-——
Based on my observations, someone has done just that. So far as we know Iran has not advanced the nuclear capability to the point of having a bomb.
It was believed in 2008 that Iran would have the bomb within a year and a half, two years tops. That was 6 years ago and apparently still no bomb.
Someone intervened, not with failed diplomacy for which there is not even a structure yet, but with action. There were not bombs dropped from the sky but sabotage on the ground. There was Stuxnet disrupting manufacturing and who knows what else. The brains running the show were forcibly removed by assassination. There were at least two reported explosions at underground facilities with large loss of life.
Obama is screwing around with unilateral negotiation because someone took direct action that was very effective
I am inclined to believe that it was not Obama but the Israelis who have done what you suggest.