ONCE the dust has settled on last week's G20 and NATO summits, the most significant outcome may well prove to be the entente reached in London between the US and Russian presidents. In a real sense, they pledged to put a final end to the Cold War – or, to quote the phrase in their joint statement, ‘to move beyond Cold War mentalities.' Barack Obama and Dimitri Medvedev obviously got on well. The photographs which captured their boyish grins told the story. They are men of the same generation, born in the 1960s within four years of each other. They are already a world apart from the era of Boris Yeltsin and George H.W. Bush, and even from that of Vladimir Putin and George W. Bush. They are leaders of the same unsettled globalized world – wrestling with much the same problems of financial meltdown, global credit crisis, unemployment, nuclear proliferation, climate change, terrorism, as well as with unresolved and potentially explosive conflicts in Afghanistan and the Middle East. Both have great ambitions – Obama to restore American leadership after the depredations of the Bush years; Medvedev to restore Moscow's ‘privileged relations' with its ‘near abroad', that is to say to bring the countries of Central Asia and the Caucasus back into Russia's sphere of influence. Neither task will be easy. Both may share another ambition, as yet not fully defined, and still possibly utopian – to eliminate all nuclear weapons on the planet, beginning with their own, as perhaps the only way to remove the threat to world peace posed by the nuclear arsenals of Israel, India, Pakistan, North Korea and – one day – Iran. Statesmen in many parts of the world have recently been arguing the merits of the global elimination of nuclear weapons. The two men have agreed to meet again in Moscow in July. The first item on their agenda then – as it was last week in London – will be a new arms control treaty. They have instructed their negotiators to prepare by July a draft of a new treaty to replace the Strategic Arms Reduction Treaty (START) of 1991, which expires this December. What is the present situation? START limited the two countries to deploying no more than 6,000 nuclear warheads on at most 1,500 strategic delivery vehicles (that is to say on Intercontinental Ballistic Missiles, submarines and long-range bombers.) This was an enormous improvement on the Cold War when the US and the Soviet Union aimed tens of thousands of nuclear weapons at each other. In 2002, Washington and Moscow reached agreement on a Strategic Offensive Reductions Treaty which capped their deployed warheads at 2,200 each by 2012 – but this agreement contained no provision for verification or monitoring. The suggestion is that the next treaty, already being negotiated, will reduce deployed warheads to 1,500 or even fewer, with a corresponding reduction in delivery vehicles, and will be verifiable and legally-binding. This is a long way from total elimination, but it is a big step in the right direction. Mohamed ElBaradei, director-general of the International Atomic Energy Agency declared himself ‘greatly encouraged' by the Obama-Medvedev agreement. A new START treaty would clearly be a stepping stone to other accords. What do the two sides want? The United States is anxious for Russian help in persuading Iran to restrict its nuclear program to peaceful uses and to agree to international verification of its facilities. Some such progress would be needed to calm Israeli fears of an Iranian bomb, and thereby pave the way for real peacemaking in the conflict-ridden Middle East. Equally important from Obama's point of view would be Russian agreement for the US to use a land route through Russia and through Central Asian states to supply its forces in Afghanistan. This is all the more vital as the route through Pakistan and the Khyber Pass has come under attack. What might Russia ask for in exchange? High on Medvedev's agenda would be the cancellation of US plans to build an anti-ballistic defence installation in Poland, along with a radar station in the Czech Republic – systems which Russia views as a potential threat. It has responded by announcing plans to deploy short-range missiles near the Polish border. Equally important from Medvedev's point of view would be American acquiescence to Russia winning back its former influence in Central Asia, which it lost in the decade and half since 1991. The fall of US-backed governments in Georgia and Ukraine would also be welcomed in Moscow. One way and another, the outline of an Obama-Medvedev deal is beginning to emerge. A wide-ranging entente between the two leading adversaries of the Cold War would make the world a safer place.