As he embarks on the uphill struggle to translate dreams into realities, one strategic goal President-elect Barack Obama should embrace on his inauguration day is that of a world freed from the threat of nuclear weapons. In doing so, he can build on an impressive body of detailed, bipartisan, unofficial policy planning in the United States. He can expect an enthusiastic response from hundreds of millions of his supporters around the world who are hoping he will think and act big. He can be equally sure of crocodile smiles masking determined opposition from several countries that possess nuclear weapons, as well as other states and dark forces who would like nothing more than to have them - and, in some cases such as the Islamic Republic of Iran, are actively working towards acquiring them.
This dream is almost as old as nuclear weapons themselves. Many of the essential elements of what is being proposed today can be found in the so-called Acheson-Lilienthal report of 1946, written in part by the nuclear scientist Robert Oppenheimer but soon buried under the rising cold war between the United States and the Soviet Union, which brought us to the edge of nuclear catastrophe. It emerges again, from the left, in the manifesto drafted by Bertrand Russell in 1955 and signed by Albert Einstein. And again, from the right, in Ronald Reagan's spontaneous offer to Soviet leader Mikhail Gorbachev at the Reykjavik summit of 1986, to which that Obama of the Soviet politburo responded: "We can do that. We can eliminate them."
So the dream has never died. But arguably we are further from it today than we were even at the height of the cold war. As Ivo Daalder, one of Obama's advisers on this issue, notes in a recent article in the Foreign Affairs journal, there are now more than 25,000 nuclear weapons in the world, and nearly 3,000 tons of fissile material - enough to make 250,000 bombs - stored in more than 40 countries. The US and Russia still maintain, on round-the-clock alert, strategic missiles capable of devastating each other's cities at 30 minutes' notice. In 1995 Russia mistook the launch of a test rocket in Norway for a submarine-launched nuclear missile aimed at Moscow, and came within two minutes of ordering a retaliatory nuclear strike on the US.
Yet that's almost the least of our nuclear worries. Far more likely is a rogue state or a terrorist group getting its hands on a few kilograms of enriched uranium or plutonium, and crafting it into a crude but still devastating bomb. And here's the new, 21st-century twist to this old story: to face another great challenge of our time, that of global warming, we will need more enriched uranium, not less. Until we achieve affordable mass usage of inexhaustible sources of energy such as the sun, using more nuclear power is one of the ways we can slow the growth of our carbon dioxide emissions. The International Energy Agency has called for 1,400 new nuclear power reactors by 2050. The devil lies in this detail: if you have the facilities to enrich uranium to the level needed for civil nuclear power generation, it's but a small step to producing weapons-grade uranium. One small step for the nuclear scientist, one giant leap for the terrorist and the tyrant.
So one reason the dream must be revived is that the nightmare, which seemed to recede after the end of the cold war, is getting closer again. Today it may be many small nightmares rather than one nightmare to end all nightmares, but small is hardly the appropriate word. In the US, the issue returned to salience with a remarkable op-ed article titled "A World Free of Nuclear Weapons", published in the Wall Street Journal in January 2007 and signed by four grand old men of American foreign policy - two of them Democrats, two Republicans: George Shultz, William Perry, Henry Kissinger and Sam Nunn. Detailed thinking has been carried forward by an initiative based at the Hoover Institution at Stanford University (where I write these lines) and the Nuclear Threat Initiative in Washington. Encouragingly, this has been a significant plank in the foreign policy part of Obama's electoral platform. The president-elect has promised to "make the goal of eliminating nuclear weapons worldwide a central element of US nuclear policy".
The question is: how? Different models are canvassed in detail, but everyone agrees that you have to do two big things. You have to persuade the states who already have nuclear weapons - whether or not they are signatories to the non-proliferation treaty - to commit themselves to reduce, rapidly and radically, and eventually to eliminate their nuclear arsenals. Zero is the goal. And you have to create an international, comprehensive, verifiable and enforceable regime covering, one way or another, the production, storage and use of all nuclear fuel in every corner of the world, so that none of it gets into the wrong hands. Each of these is, on its own, a tall order. But you have to do both.
Britain has already signed up in principle to the logic of zero, although at the same time justifying the modernisation of its nuclear deterrent by a very broad rationale of keep-hold-of-nurse in an uncertain world. But what about France, China or India? Let alone Israel and Pakistan. And, of course, Russia. Russia and the US between them account for 95% of the world's nuclear weapons. Without Russia, you won't get far. Of late, Russia has not been happy with the west in general, and the US in particular. Among its particular gripes are the promise of Nato membership for Georgia and Ukraine, and the stationing of US-led missile defence facilities in Poland and the Czech Republic. It will require statecraft of a high order, from European capitals as well as from Washington, to persuade Russia to regard this as a joint project for humankind and not just another western plot.
For historians, there's a particular paradox in the missile defence angle. As you can see from the now declassified records of the Reagan-Gorbachev conversations at the 1986 Reykjavik summit, what kiboshed the briefly flowering consensus on eliminating all nuclear weapons was the Soviet Union's implacable opposition to Reagan's Strategic Defence Initiative and Reagan's equally unshakeable commitment to proceeding with it. Twenty-two years on, missile defence, the nephew of SDI, may become an early diplomatic obstacle to reviving the Reykjavik dream.
No, none of this will be easy. And negotiations with established nuclear powers will be a cakewalk compared with the second task: that of creating an effective international regime to supervise the production, storage and use of all nuclear fuel everywhere in the world. I can well imagine some hardnosed pragmatists on Obama's transition team urging him not to include this among his three or four headline foreign policy priorities: too ambitious, too difficult, not urgent. But I hope he will overrule them, and that his supporters around the world will then rise to sustain him on the way, making this a genuinely common endeavour. Yes, this is trying to close Pandora's box, and no one has done it before. But there's a first time for everything.
Timothy Garton Ash