There is no contradiction of possibilities or alleged facts to say that 23 years ago Iran had no centrifuges and that now they have a lot of them. The Politifact article though is indeed interesting and presents a scenario I have not seen addressed elsewhere.

 I do believe that monitoring of known enrichment sites would be, already is, stringent enough to identify any move towards breakout and that any attempt to produce weapons grade material secretly would need entirely new secret facilities. That would be a great risk to Iran which, if discovered as it almost certainly would be, would remove any doubt as to their ultimate intentions and would almost certainly result in a joint U.S. and Israel military response. That would be a risk which I doubt Iran would feel the need to take if they were experiencing the relief that an agreement would provide them. I suspect that a reason, not the only reason, Iran has pursued nuclear development the way they have is to create a bargaining chip which they are willing to give up in a bargain but if that is a tactic it creates a game of chicken which will probably force them to try for a bomb if the negotiations fail. Iran has their hawks and no doubt their fair share of chicken hawks playing political gamesmanship too. Failure to come to an agreement with Iran would be, IMO, a sad and tragic slip-slide towards a military attack on them and the possible results of that are cataclysmic. We cannot, IMO, keep on trying to rule the world with military interventions or the threat of same without eventually bringing down our own house. The chances any real attempt to forge a cooperative peace entail are worth taking when the sure fire result of constant war is that we will eventually lose.

 Thanks for those links.