Mr Clinton arrived from Brussels, where disagreements over Bosnia soured the air of unity at the conclusion of the Nato summit. Continuing splits over the use of force against Bosnian Serbs showed that, despite a successful meeting, the task of adapting the alliance after the Cold War was proving tough. The fate of an agreement with Kiev to scrap all Ukrainian nuclear weapons also appeared to be in doubt.
In talks last night with the Czech President, Vaclav Havel, Mr Clinton spelt out Nato's Partnership for Peace, under which former Warsaw Pact countries will, for the first time, be invited to participate in joint military manoeuvres with their old adversaries. Today he is due to repeat the exercise with the presidents of Poland, Hungary and Slovakia.
Although all four Central European countries, known as the Visegrad group, had wanted a great deal more - a firm timetable for Nato membership and binding security guarantees from the West - they have been forced to accept that the Partnership for Peace was all they could realistically expect for now. The Czechs, Slovaks and Hungarians had, albeit grudgingly, all signalled acceptance of the plan before Mr Clinton's arrival. President Lech Walesa of Poland remained scathing to the end, at one point threatening not to attend today's meeting with Mr Clinton in protest over the lack of firm commitments.
Mr Walesa's abrasive tone in part reflects the fact that Poland is the country which feels most threatened by a resurgence of nationalism in Russia. But it also indicates the deep divisions that have emerged within the Visegrad group over how it should deal with the West.
For the past few months the Czech government has made it increasingly clear that it does not want Visegrad to become an institutionalised bloc, faintly reminiscent of the old Comecon or Warsaw Pact, and that, in fact, it might prefer to try to go it alone.
Vaclav Klaus, the Czech Prime Minister, sees Visegrad - named after the Hungarian town where the presidents of Poland and Czechoslovakia and the Prime Minister of Hungary met in 1991 - as a loose association of countries focusing on economic rather than political goals.
Such aloofness has ruffled feathers in the other three countries, with President Walesa in particular railing against the 'arrogance' of Prague.
Nato's Bosnia plans, page 10
Ukraine's fears, page 16