Rather a glum perspective :/
Worldwide disarmament is not an impossibility. In fact it's increasingly vital, and the rouge states (including, regrettably, my own country) that still insist on keeping WMD's are increasingly embarrassing and dangerous.
I think the loathing between Israel and Iran is pretty much mutual, to be fair to the iranians.
Problem is, there's always going to be one country that's the last to disarm. In the global power scene, that's likely to be either Russia or China - which spells a rather grim future for hundreds of millions of people in their power sphere.
I think the status quo of carefully maintained stockpiles of nukes among superpowers is pretty sustainable, because all the superpowers have an interest in their own survival. The thing that really caused things to unravel is the nuke trade, which led to less stable countries like North Korea, and active enemies like Pakistan and India, getting nukes.
