'October Surprise'

"... Still, if Iran’s leaders were Western-leaning democrats (read less anti-Israeli), their nuclear program would be less worrisome......  if the Iranians’ nuclear program has a military dimension (as it almost certainly does), one motive driving it is the old-fashioned doctrine of deterrence: They want a nuclear arsenal in part to deter their enemies, chiefly the United States and Israel, from launching an attack on their regime.......  it’s extremely unlikely that a nuclear-armed Iran would one day, out of the blue, start dropping bombs or firing missiles at Jerusalem and Tel Aviv. For one thing, whatever the status of Iran’s nuclear-enrichment program, they are probably years away from turning an explosive device into a weapon, miniaturizing it to fit inside a warhead, and installing the warhead on top of a missile heavy enough to deliver it over a long distance with accuracy.
For another thing, Israel is believed to possess up to 200 nuclear weapons......
Some have inferred from this argument that an Iranian bomb is nothing to worry about. This inference is wrong, for several reasons. First, nuclear weapons are good not just for deterring but also for brandishing. They can provide cover for conventional aggression or intimidation. ........... a nuclear-armed Iran may push or condone the more militant factions within Hezbollah and other proxies to step up their aggression and take greater risks.... ....
I don’t think the Iranian nuclear program constitutes an urgent danger. But if there is a way to nip this whole panoply of nightmare scenarios in the bud—if there’s a diplomatic route to keeping Iran from going nuclear—then it’s worth pursuing, at some effort and cost.
The good news is that the sanctions have been taking their toll on the Iranian economy and its international standing. If the Supreme Leader really does think nuclear weapons are immoral (as he has said), or if there are factions within the government that think the pursuit of a bomb is costing too much, then maybe this weekend’s talks will bear fruit.
The bad news is that, for the Iranians to give up such a high-profile trump card, they need to get something in return—a suspension of sanctions, a guarantee of security, something that’s tangible and valuable. Is there some deal—even hypothetically—that is, at once, worthwhile to the Iranians and acceptable to the Israelis? That’s the key question; it’s hard to envision such a thing.
In fact, if the Israelis really are intent on attacking the Iranian nuclear facilities, they’re likely to do so before this November’s American presidential elections. If they started an attack and needed U.S. firepower to help them complete the task, Barack Obama might open himself up to perilous political attacks—for being indecisive, weak, appeasing, anti-Israel, you name it—if he didn’t follow through. It could cost him the votes of crucial constituencies. If the Israelis tried to pressure the United States into joining an attack after the election, Obama would have (to borrow a phrase from another context) more flexibility. So, to the extent the Israeli leaders have decided to attack (and it’s not at all clear they have), they are probably thinking: much better sooner than later...."