President George Bush and President Vladimir Putin are embarking on what may be the most momentous US-Russian summit since the end of the Cold War, with talks in Washington and Texas that are expected to lead to an understanding on missile defence and agreement on a new round of deep cuts in the two countries' nuclear arsenals.
In a fashion unexpected by almost every analyst, the two months that followed the terrorist attacks in the US have helped assemble the ingredients for a new strategic alignment between the two former superpower rivals. In a host of areas, from trade to economic co-operation as well as the campaign against the al-Qa'ida terrorist network, the interests of Washington and Moscow are suddenly no longer competitive but complementary.
There are no plans for a new formal arms treaty between the US and Russia. But in recent days Mr Putin has signalled that he is ready for a compromise that would allow Mr Bush to proceed with testing his cherished missile defence system without formally breaching the 1972 Anti-Ballistic Missile treaty, which Moscow views as a cornerstone of nuclear arms control agreements.
At the same time, both countries favour steep reductions in their nuclear arsenals, currently about 6,000 to 6,500 warheads apiece. Russia, strapped for cash to maintain its existing stockpile, wants to slash the number of deployed warheads to 1,500. The Pentagon, slightly more wary, is reluctant to go much below 2,000.
But more importantly, Mr Bush and Mr Putin have found themselves on the same side in the war against terrorism. Embroiled in its own brutal war to suppress separatism in Muslim Chechnya, Russia sees America's offensive against terrorism in Afghanistan and elsewhere as an extension of its own.
To the deep gratitude of the US, Mr Putin has been instrumental in securing the co-operation of the former Soviet republics of Uzbekistan and Tajikistan – which Moscow still considers very much within its sphere of influence – with the US logistical build-up in the region. In return the US is considering the repeal of the 1974 Jackson-Vanik amendment that imposed conditions on Soviet trade with the US. This could hasten Russia's entry into the World Trade Organisation.
For its part, even though its relations with Nato remain touchy, the Kremlin has signalled it might be less hostile to a new round of expansion by the alliance into the Baltic countries, which until 1991 were part of the Soviet Union.
The summit is split into two parts which could hardly be more contrasting. The first day in Washington will be devoted to weighty matters of state – the campaign against terrorism, the future of Afghanistan and nuclear arms control – with its high spots a joint press conference at the White House and what Russian officials say will be a major speech by Mr Putin in the evening.
Tomorrow, high formality will give way to homely life on the range, when the Russian leader will spend 24 hours on Mr Bush's 1,600-acre ranch, called "Prairie Chapel". It may be an otherwise undistinguished chunk of flat central Texan plain, cut by shallow canyons. The local metropolis is Crawford, boasting only 700 inhabitants, one traffic light, no hotels or bars, but four churches.
But Mr Bush, who never misses a chance to stress his affection for the place, has made clear that his invitation to Mr Putin and his wife, Lyudmila, reflects the warm personal relationship between the two leaders. "As the two of us work through these times of diplomacy and times of war, it is important to get to know each other really well," Mr Bush said last week.
The evening mood will be further enhanced by a barbecue, complete with a cowboy chuck wagon. As they down their tenderloin beef and pecan pie, diners will be serenaded by what the First Lady, Laura Bush, last week called a "great little Texas acoustic combo", playing such melodies as "Drifting Along With the Tumbling Tumbleweed" – big local favourites but the Putins may find it all somewhat bemusing.Reuse content