Before I begin, I have to say a few things. I am far from a Barack Obama fan. I cannot stand his policies, nor can I stand the fumbles he has made politically abroad. That said, I do admire his effort in this. Nuclear weapons, both A bombs and H bombs, are right near the top of the list of things the world would be better off if they were never invented, right behind New Coke and Crystal Pepsi. Where this summit loses credibility however, is the list of nations who are not here.
Israel - In this case, I'm not sure if the president was arrogant or merely stupid. You can't smack a proud group of people around diplomatically as he as done in the past few months and expect them to show up for your round of holy pictures. Besides, it's the world's worst kept secret where most, if not all, of Israel's nuclear capability has come from. It was 6-5 and pick 'em whether the Israelis were going to come anyway, now they have a legitimate, albeit not the real, reason to stay home.
North Korea and Iran - Two more nations that are notable for not even being invited. I will discuss them together as the reasons are similar. The White House claims that, due to their non proliferation violations, neither country were going to be invited. In my opinion, that is a huge reason for them to be here. Those two countries do not have the fear of the bomb that the rest of the nuclear nations do. They will continue to advance their technology to the point that they can build any device they want. Also, if the price is right, they will have no problems selling ready made devices to the highest bidders. Having leaders from those two nations in the same room with all the other nuclear powers to hear other opinions may have had an effect on their policies. We will never know now though. Thankfully China seems to, at least publicly, want to work with the United States to keep Iran and North Korea in line. I understand North Korea, as China has had them on a fairly short leash for a while now, but how would China have any influence over Iran at all? UN sanctions? Yea, like that works.
Another aim of these talks, some would say the primary aim, is to control readily fissionable material. There are reports that there is enough plutonium and highly-enriched uranium around the world to build 120,000 nuclear weapons. Again, another admirable goal on paper. When you consider that the average plutonium core for a nuclear weapon averages 5kg (approx. 11lbs), it wouldn't be hard to hide/smuggle enough for a bomb or two to radical groups. How can you stop it all? Yes, controls over production, transport, and distribution of fissionable materials are very good in most of the nuclear nations. It's the ones that don't have good records or control that are going to be a problem.
While the intent of the summit is good, I feel that this is nothing more than a feel good exercise for the president after the bloody battle he just fought over health care.