According to a senior Nato diplomat, the alliance is bracing itself for renewed Yugoslav military activity in an attempt to "try to pose some tests for the alliance by ratcheting up the pressure on the ground".
Yugoslavia's President, Slobodan Milosevic, could pursue at least one of three options, the alliance believes, all of which could increase the political and diplomatic embarrassment of the 19 leaders as they gather in Washington tomorrow.
The first is to step up hostilities against the guerrilla fighters of the Kosovo Liberation Army on the ground inside Kosovo. According to Nato, Belgrade is concentrating its forces for an offensive in two regions of of Kosovo; in the north, around the towns of Kosovska Mitrovica and Podujevo, and in the west, between Prizren and Djakovica. Nato has also noticed what it describes as "clearance operations" in the Kosovar capital, Pristina, in which, it claims, tear gas has been used.
In addition, Mr Milosevic might start a new round of forced expulsions from Kosovo timed to take place while the alliance leaders are meeting. Nato says that President Milosevic can organise another chaotic exodus whenever he chooses, as his forces have herded many of the displaced civilians close to Kosovo's borders in the south, but has not allowed them to cross into Macedonia or Albania.
Finally, Nato is bracing itself for an escalation of Serb pressure on neighbouring countries such as Albania, Macedonia and Croatia, and on Montenegro, which is part of the Yugoslav federation but has sought to remain outside the conflict.
"We know President Milosevic is a man who thrives on a crisis," Jamie Shea, Nato's spokesman, said yesterday. "We have to be on our guard, we have to be vigilant for any attempt to create, out of a domestic crisis, an international crisis".
The Prime Minister brought his flight from London forward by two hours to fit in the meeting at the White House, underlining the importance he attaches to holding talks with Mr Clinton before the summit.
Planned over 18 months as a celebration of a successful 50 years searching for a less overtly military role in the next century, the summit has been transformed into a council of war. With the alliance edging towards the use of ground forces, the Prime Minister's official spokesman yesterday confirmed that Mr Blair would discuss all the military options with Mr Clinton.
"They are going to discuss the whole issue. The Prime Minister has said Milosevic has no veto on troops going in and that is still the position," the spokesman said
It is likely that Mr Blair and Mr Clinton will try to clarify their approach to the use of ground forces - both London and Washington are still opposed to such a move. Mr Blair told Russian television yesterday: "We of course keep all options under review... but it is important to recognise that this air campaign is working and will work."
After meeting President Clinton, Mr Blair will deliver a keynote speech today in Chicago on Kosovo and Britain's place in the world.Reuse content