Rather than make this all complicated and require Wolf Blitzer an hour to explain things....let's do it in sixty seconds.
First, thirty-one countries have nuke power today in some form. Nine countries have nuke weapons in some form. How quick would it take Brazil, Czech or Finland to flip over to nuke weapons? Probably less than three years. Once you have the technology of nuke power.....it only takes a bit of experimentation or acquired technology from North Korea.....to settle into an accomplished goal of weapons.
Second, what the treat discussion here is really about.....is a brake-job or delaying Iran from nuke weapons for approximately a decade (might even be less than that, if they wanted to just skip the last part of the treaty). So the value of the treaty is for the US is stand and admit there's nothing to hinder or stop this process....we will simply let things develop as they are.
Third, once Iran has nuke weapons.....what exactly do you think their neighbors will think about and consider? Their own nuke weapons? Iran, Syria, Saudi Arabia, Turkey? The Saudis currently have no nuke power generator. It'd take a simple contract with a French power company to get over to step one......build a nuke plant, and then bring in some South African or North Korean engineers to build up the secondary arm of nuke weapons. Ten countries in the Middle East by 2030 with nuke weapons.....if Iran proceeds ahead? It's a safe bet to make and put some money on.
Fourth, Israel and Netanyahu simply want the poker game to keep playing out with economic sanctions and military strategy. We are probably on poker game version forty-two at present and Iran has figured out how to play poker in an effective manner. Iran can't lose.....while they might be on a long-term strategy, they don't care about short-term losses.
Fifth, President Obama and Netanyahu? Basically.....two guys who have each run out of likability and flexibility. Netanyahu is up for election, and some Democratic Party wise-guys have shown up to help against his election chances. Bad strategy if you ask me.....but meddling in politics is now a daily event in US politics. Netanyahu has countered the White House strategy and now in their own backyard....something that they never envision.
The only option left besides signing some marginal treaty with Iran? Basically dig up fifteen Democratic senators who will side with the Republicans and vote prior to the treaty.....saying 'no' support, period. It'll make the President look weak, as well as the Secretary of State.....but we are at some point where there's nothing much to gain.
Bottom line? There's a nuke war to come sooner or later out of this, and it might not involve the Iranians versus the Israelis.....it might be involving the Saudis, and there might be some religious mullah folks who trigger the event. Then what? To have twenty-five nuke missiles fired off within a span of an hour and half of Riyadh and Tehran destroyed? Would it bother us that much? I think the White House is simply saying 'no'.....they don't care anymore....let the nuke scenario play itself out.
That's the simplicity of this discussion.....nukes actually going off and some people wising up over stupidity.