The new Start treaty signed by Presidents Obama and Medvedev in Prague is possibly the last rite of passage from the strategic certainties of the Cold War to the discordant perils of today's fragmented world. From the signing of the first Strategic Arms Limitation Treaty (SALT) in 1972, codification of the 'central balance' between the United States and the USSR disciplined and constrained the rivalry between them as well as the ambitions and animosities of other countries. Those disciplines collapsed with the Berlin Wall, and if the collapse of the Twin Towers twelve years later did not make the point obvious, nothing will.
The relationship between the US and Russia no longer defines what is possible and what is not. The calculations of the world's emergent nuclear states such as India, Pakistan and Israel are distinctly more urgent and parochial, and the Prague summit is unlikely to alter them. The regimes in Iran and North Korea will be as impervious to the new treaty as they have been to everything else.
Even the US and Russia have altered their horizons. With pronounced anxiety and very mixed results, each is trying to adapt nuclear and conventional forces to threats that are more inchoate and asymmetric than any conceived by the architects of strategic arms control.
For all that, the treaty has a good deal to be said for it. Rejection by the US Senate would not advance either country's relationship with China, for which the main point of Prague was its own exclusion. The treaty's slow death on the Senate floor would divert attention from the threats that really confront the United States. Paradoxically, it would also delay discussion of how to respond to the geo-economic and 'civilizational' challenges posed by Russia in its post-Soviet neighbourhood and to several new NATO states. Worse, the spectre of US Senators attaching Cold War-era significance to imperfections regarding verification mechanisms will further blind Russia's military establishment to the obvious: the Pentagon's support for the treaty.
Yet whatever the treaty's reception in Washington, Russia will create its own complications. Although there is nothing binding in the recognition of 'the interrelationship between strategic offensive arms and strategic defensive arms' (pg 2), President Medvedev asserts that a 'legal relationship' exists. The once somewhat open, now strictly classified, discussion of 'preventive nuclear attack against the aggressor' (in the words of Nikolai Patrushev, Secretary of the Russian Security Council) in the context of regional war was sharpened by the 2008 war with Georgia as well as the development of US global strike conventional weapons. The Russian military (and much of the political) establishment retains the view that 'the adversary stays in the wings and pretends there is a partnership'.
Partnership in Russia, and more specifically the leadership tandem, is also a complication. As President Obama stated in Prague, the Start treaty owes much to the 'personal efforts' of President Medvedev. The past and possible future president of Russia, Vladimir Putin, who chairs the United Russia party (and de facto the Russian State Duma) might view this as an occasion to remind both presidents that Medvedev's personal efforts are not enough.
Yet the odds of Putin blocking ratification are distinctly less than they would have been one year ago. The financial crisis has had a withering effect on Russia's defence establishment. It has also given impetus to the first thorough military reform since the USSR collapsed. More tellingly, Russia's strategic nuclear deterrent is threatened with decomposition. The failure of the Bulava missile - and with that, Russia's entire sea-based modernization programme - renders unregulated competition with the United States ruinous to Russia's interests.
The fact remains that, in recent years Russia's capacity to damage itself has proved even greater than its capacity to damage others. The same can be said for the United States. The fate of the Start treaty will say even more about the strategic wisdom of these two countries than it will about their strategic interests.