The stage is set for the signing in Prague of the first arms control treaty of the Obama era. It is the initial step on the road to the US President's declared goal of a world without nuclear weapons, which he vibrantly described in the Czech capital a year ago.
But now that the applause has died down after the US and Russia reached agreement on capping their deployed long-range nuclear weapons in the Strategic Arms Reduction Treaty (Start) follow-on pact, the treaty's limits have become apparent. The Obama administration says that it will curb the deployment of strategic weapons by one-third, leaving each side with 1,550 operational warheads, but that number is still enough to destroy the planet several times over.
It is a far cry from 1987, when the Soviet Union and United States agreed to eliminate an entire category of weapons by signing the Intermediate-range Nuclear Forces agreement.
As Obama looks ahead to the next steps in his security agenda, there is an opportunity for real disarmament, in the heart of Europe, which would lead to the removal of the 200 or so US nuclear weapons from five European countries under the Nato umbrella.
We don't know how many there are exactly because we have never been told. They are holdovers from the Cold War, when they were deployed secretly in Belgium, Germany, Italy, the Netherlands and Turkey under bilateral agreements with Washington.
Why do we need them? We don't. They have been quietly removed from Britain and Greece. It is widely held, even by the military, that the remaining B61 gravity bombs serve no military purpose and will never be used. At a time of war, it would take weeks for them to be operational on US aircraft capable of carrying nuclear weapons – which are no longer stationed in Turkey anyway.
Germany, the first Nato country to raise its head above the parapet to seek the weapons' withdrawal, will soon have to bite the bullet and decide whether to invest at huge cost in dual capable aircraft to carry bombs which it officially wishes to see removed.
Russia certainly isn't trembling at the thought of these obsolete weapons in need of refurbishment stored on US bases around Europe. So it should be easy to get rid of them, right?
Wrong. The German foreign minister, Guido Westerwelle, and four of his European counterparts, have at least succeeded in having Nato discuss the issue for the first time at a foreign ministers' meeting in Tallinn, Estonia, later this month. In a letter to Nato secretary-general Anders Fogh Rasmussen in February, the five urged the Western military alliance to move its own nuclear doctrine closer to the US President's overall objective of a world free from nuclear weapons.
But as the once-taboo issue has come to the fore, so have the arguments against the tactical weapons' removal as the Nato establishment has mobilised. We have heard warnings of the danger of unilateral action: why should we give Russia something for nothing, by meeting a long-standing Russian demand to take the weapons away?
The alliance itself is bitterly divided, with the former Soviet bloc states wary of a perceived concession to Moscow. They had become used to seeing the weapons stationed in Western Europe as a way of coupling the United States to European security and as protection against the Russian bear – which has an estimated 2,000 to 5,000 tactical weapons of its own.
But these weapons are worthless as a bargaining chip as Russia must have discounted them long ago in its strategic planning. Russian military experts point out that the reason Russia keeps such an overwhelming superiority in tactical nuclear weapons is to balance the US superiority in conventional weapons. Not to mention its strategic concerns about China.
The Obama administration remains attached to holding a further set of negotiations with Russia after the Start follow-on treaty that will be signed in Prague. Administration officials talk about "conversations" on the tactical nuclear weapons with Moscow, not necessarily a treaty which could run into trouble in the currently toxic political atmosphere here in Washington.
Engaging with Russia on its broader security concerns is certainly the correct way forward, for both the US and Nato. The main significance of the Start follow-on treaty lies in what it says about the improved diplomatic relationship between Moscow and Washington. But the countries of central and eastern Europe still need to be reassured about their security.
Nato's own response will emerge over the next few months as the alliance holds its own Strategic Concept Review, its first consideration of the role of nuclear weapons in Nato doctrine in a decade.
More broadly, the global commitment to disarmament will be tested next month, when the 189 member states of the Nuclear Non-Proliferation Treaty gather in New York for a five-yearly review conference to renew their vows. It would be encouraging if the five nuclear powers – Britain, China, France, Russia and the United States – reaffirm their "unequivocal" commitment to nuclear disarmament in a statement which is currently being drafted.
Indeed, Britain, France and China may feel the heat if Obama pursues disarmament steps which would force them to include their own nuclear arsenals at a later stage. In Prague last year, he served notice that once agreement on Start follow-on was reached, it would set the stage for further cuts, "and we will seek to include all nuclear weapons states in this endeavour."
A crucial arbitration will be contained in the long-awaited US Nuclear Posture Review, whose conclusions, expected tomorrow, will reverberate around the world.
The document will be scrutinised to see whether it gives the nod to Nato to pursue its consultations on the removal of the tactical weapons from Europe – at a time when the Obama administration has let it be known it would respond to a Nato request.
Above all, it will be the first concrete indication of whether Obama has the military establishment of his country behind him in seeking to reduce the role of nuclear weapons in US war plans.
Anne Penketh is Washington Program Director of the British American Security Information Council (Basic)