Nuclear arms summit and certain nuclear-able countries

Today our president is convening a nuclear arms summit, with the avowed purpose of making sure that all material that can go to making regular nuclear weapons are under firm control of the various governments of those countries that have them, so that they don’t fall into the hands of terrorists.

(Some are more afraid of dirty bombs, but that doesn’t seem to be the focus of this summit.)

I would be surprised if there wasn’t also something on the agenda to prevent more “rogue nations” like Iran and North Korea from successfully developing nuclear weapons, or maybe they just fall in the category of terrorists.

Then you have certain countries that already have nuclear weapons:

Pakistan - unstable, temporarily semi-friendly to the US, but my bet would be they won’t be too interested in these goals, not enough to allow any oversight of their nuclear weapons or materials. Probably already responsible for selling nuclear technology, if not materials, to various unsavory governments and possibly other organizations.

Israel - everyone “knows” that Israel has nukes, but they resolutely refuse to confirm or deny. They certainly aren’t going to be willing to talk about what nuclear materials they might have. Their PM decided not to go to the summit, but is sending someone lower down instead.

(Why do I have Lehrer’s song “Who’s Next?” running through my head? “Israel’s getting tense, they want one in self-defense. ‘The Lord’s our Shepherd’ says the Psalm, but just in case, we’d better get a bomb!”)

My question is, isn’t this horse already way out of the barn? Is there any way this summit can succeed in any of the above-mentioned goals? Russia and the Europeans will probably play nicely (possible exception for the French, you never know about them). The others I have doubts about.

I’m not presenting a strong argument either way, I would be very interested to hear what more informed folks think.
Roddy