In Belgrade, state companies and organisations were placed on a war footing, and the authorities ordered the expulsion of foreign journalists representing Nato countries. Dashing any Western hope that one dose of destruction would suffice to force him to accept a Kosovo settlement, the Yugoslav President praised his military for their "brave resistance" and broke off diplomatic relations with Britain, the United States, France and Germany.
Most ominous of all were signs that the fighting could spill over into neighbouring countries - and that an air campaign intended to bring peace would instead lead to the biggest war in Europe in half a century.
After Serb forces shelled villages in north-eastern Albania and hundreds of new refugees flooded across the border, Tirana's Foreign Minister flew to Brussels to seek Nato guarantees of protection against any major attack from Yugoslavia. The frontier was described as "very hot" with exchanges of fire between Albanian and Serbian troops.
Tension mounted, too, in Macedonia to the east, where 1,500 people staged a noisy demonstration outside the US embassy in the capital, Skopje, protesting at airstrikes and the presence of more than 10,000 Nato forces in the country.
If Mr Milosevic was to blame for the humanitarian disaster in Kosovo which has sent 20,000 ethnic Albanians fleeing into Macedonia, the Prime Minister, Ljubco Georgievski, pleaded, "the spill-over... is the responsibility of the US and the EU".
Elsewhere, border crossings into Yugoslavia were sealed, Romania shut its airports close to the border, and security controls were tightened across the region, from Slovenia in the north to Greece in the south.
According to the Yugoslav military, 10 people were killed and dozens more injured on Wednesday night in what the Belgrade Defence Ministry yesterday called an "unprecedented criminal act" in support of ethnic Albanian "terrorists".
It had been a massive opening salvo, as Nato jets and cruise missiles pounded more than 40 targets in the first night alone.And last night the allies were meting out more of the same, led by USS Gonzales, which sent 18 Tomahawk cruise missiles streaking off into the twilight.
"There is no sanctuary," said US General Wesley Clark, Nato's supreme commander. "We are going to grind away at him. We are going to systematically and progressively attack, disrupt, degrade, devastate and ultimately - unless President Milosevic complies with the demands of the international community - destroy his forces and their facilities and their support."
Western politicians started to prepare public opinion for a long campaign of attrition. Only if the violence ended in Kosovo would President Milosevic secure an end to the raids, George Robertson, Secretary of State for Defence, declared. The crisis was the sole responsibility of the Yugoslav leader, Robin Cook, the Foreign Secretary, told the House of Commons; Nato had been left with no other way of preventing a humanitarian disaster.
That argument seems to be prevailing, however uneasily. But there were open dissenters in both Labour and the Opposition, led by the former Labour cabinet minister Tony Benn, who condemned what he called the Western "war of aggression". Voicing doubts of the legality of the Nato campaign, he accused the allies of violating the founding charter of the United Nations, as well as the core principles of the Labour Party.
For a brief moment, hopes flickered yesterday that the humanitarian crisis might be about to ease, as the Italian Prime Minister, Massimo D'Alema, suggested that Serb forces had ceased their onslaught against the ethnic Albanians. But that was swiftly denied in Washington by Sandy Berger, President Bill Clinton's national security adviser.
And as dusk fell across the Adriatic last night and Nato warplanes again lifted off from Italian airbases, the facts seemed to bear Mr Berger out. Serb police ruthlessly shut down Kosovo's last Albanian language newspaper, Koha Ditore, shooting dead an office guard. Across the province, more villages were ablaze, while 1,700 Muslim Albanian refugees have fled to western Turkey this week alone - strengthening alarm that the bombings may deepen the humanitarian catastrophe they are intended to prevent.
To some experts, the Serb military operations suggested that President Milosevic was trying to sweep ethnic Albanians from the north of Kosovo before annexing it, leaving Nato to take charge of the southern rump. The problem with that theory is that most of the great Serb Orthodox religious sites are in southern Kosovo, close to the border with Albania.Reuse content