With peace talks on Kosovo deadlocked last night NATO member embassies got ready to evacuate the last of their staff while Yugoslavia prepared to go on to a war footing.
The United States envoy, Mr Richard Holbrooke, said last night that while he expected to keep talking with the Yugoslav President, Mr Slobodan Milosevic, he believed NATO would today give final permission for air strikes to be launched.
Despite a marathon session of talks yesterday there was no sign of Yugoslavia agreeing to NATO demands to pull troops back in Kosovo, allow refugees to return home and begin peace talks with ethnic Albanians.
But the talking is expected to go on all through today. "I don't think it's a secret but it is going to be a very long night," said one western diplomat in Belgrade. "And a long day tomorrow".
This morning a convoy of more than 25 vehicles led by the United States embassy is expected to take staff from all western embassies apart from those of Poland and Austria, which will remain open to offer a European Union representation in Belgrade. Meanwhile Yugoslavia, while declaring it is ready for peace and complying with NATO demands, is preparing for war. Emergency powers are being prepared which include food rationing and arrest without charge while the armed forces have been put on a high state of readiness.
Ordinary Serbs are meanwhile preparing for the worst, having been told by the state-dominated media that NATO jets will strike at civilian as well as military targets.
Every home in Belgrade has been sent a leaflet explaining what to do if the air raid sirens go off, and deep shelters built during the Cold War are being dusted down.
A Belgrade student, Dusan, said he has stockpiled candles, batteries, food and fuel for the bombardment and the chaos that may follow. A fellow student who would not be named said: "I know where all the shelters are, but if they bomb I am heading for the basement of the nearest drug store. In those places you are sure to have enough food and drink."
Official propaganda blames western journalists for spreading lies among NATO countries which have contributed to the air strike threat, but on the streets of the capital the mood among Serbs is of suspicion rather than hostility, mixed with a goodly portion of paranoia.
Belgrade television has repeatedly screened programmes showing army and air-force units preparing to do battle with NATO, with footage of plunging fighter planes and soldiers in underground complexes played to a backdrop of stirring patriotic music.