The nuclear arms reduction agreement that could be formally announced today by the US and Russia is numerically modest. Nevertheless, it is probably the most important such deal between the former superpower rival since the end of the Cold War two decades ago.
The "New Start," as the agreement replacing the now-expired 1991 Start deal is known, will cut the ceiling for long-range strategic warheads on each side to around 1,500 or 1,600. This compares with the existing ceiling of 2,200 contained in the 2002 Moscow Treaty signed by Presidents Putin and George W Bush.
There will also be small cuts in the number of launchers – ie missiles, submarines and long-range bombers – that deliver the warheads. The US is believed to have around 2,150 deployed nuclear weapons, the Russians some 2,600.
From a purely military point of view, the deal was more important to Moscow, given the budgetary burden of maintaining and securing its stockpile. But the Kremlin played tough almost to the end, digging in its heels over verification procedures and missile-defence issues.
But Presidents Barack Obama and Dmitry Medvedev cut through the major outstanding issues in a phone conversation earlier this month. "New Start" is set to be signed at a ceremony in Prague on 8 April, a year almost to the day after Mr Obama's speech in the Czech capital calling for a nuclear-free world.
This helps explain the political importance of the agreement for Washington. Not only is it a foreign-policy success to set alongside his domestic victory on health care, but the deal is also a perfect symbolic curtain-raiser for the nuclear-security summit to be held there in April, and for the 2010 Nuclear Posture Review, setting out overall US nuclear strategy, due to be released soon by the Obama administration.
Global attention may be fixated on nuclear and potential nuclear "rogue states" such as North Korea and Iran, and on the arsenals of relative newcomers to the nuclear club such as India and Pakistan. But action must begin with the US and Russia, accounting between them for more than 90 per cent of the world's nuclear weapons. Moreover, Russia is the only country posing an existential nuclear threat to the US.
But even after signature, a treaty will not become law until ratified by the Senate – and there "New Start" could hit problems. Such difficulties would not be new: the US has signed but still not ratified the 1996 Comprehensive Nuclear Test Ban Treaty, and in the best scenario, the new pact may not be approved before the 2010 mid-term elections.
Treaties need a two-thirds majority for Senate approval, meaning that at least eight Republican Senators must support it. Given the present toxic climate on Capitol Hill, that is no sure thing. Last week, Mitch McConnell, the Republican leader, wrote to Mr Obama warning that ratification would be "highly unlikely" if the treaty contained any binding linkage to US missile-defence programmes. The administration insists it does not.Reuse content