Nuclear disarmament can't escape realpolitik
We have just had the second Nuclear Security Summit in Seoul. It got surprisingly little attention from the international media although over 50 countries attended. Nobody expects a nuclear war, but a nuclear weapon in terrorist hands is the defining nightmare of the post-9/11 decade.
Keeping bomb-grade nuclear material out of the wrong hands requires a high level of international co-operation. Some progress was made on this issue in Seoul, but the real problem is that there are far too many nuclear weapons in the world.
The only plausible source of a terrorist bomb is the nuclear weapons programmes of the various states that own them. And the bigger those programmes are, the greater the chance that either a nuclear weapon or a large amount of fissile material will fall into the wrong hands.
Now, it may be true that the US nuclear weapons establishment is so efficient and experienced that there is little risk of anybody stealing American bombs or fissile material. But American security also depends on everybody else's nuclear establishments being well protected - and this explains why US President Barack Obama is a strong supporter of the 'Global Zero' project.
From a high of 65,000 active nuclear weapons in 1985, the world's stock has declined to about 8,000 active warheads now, 95per cent of them under Russian or American control. There are an additional 14,000 nuclear weapons in storage, all of them Russian or American - and those may be an even greater danger for nuclear terrorism, since they are not under hourly supervision.
Getting the number of active nuclear weapons in American and Russian hands down to 1,000 each, and dismantling all the 'reserve' and stockpiled weapons, is probably Obama's real goal.
However, to get Russia to sign up to that, Obama will have to give up on ballistic missile defence. The Russians are hugely inferior to the Americans militarily by every other measure, so they cherish their nuclear parity. Effective US missile defences, if they could ever be made to work, would fatally undermine that parity.
Abandoning them would involve Obama in an immense battle with the Republican right, and he's not going to start that battle in an election year. But that is what Obama and Dmitry Medvedev, the outgoing Russian president, were really talking about in Seoul when they were caught on an open mike.
Obama told Medvedev: 'On all these issues, but particularly missile defence, this can be solved but it's important for [incoming Russian president Vladimir Putin] to give me space ... This is my last election. After my election, I have more flexibility.' And so he may.
Gwynne Dyer is a London-based independent journalist