Commanders, frustrated and angered by a stymied bombing campaign and the seeming inability to dent significantly the Serbian war machine or stop the waves of ethnic cleansing, say the real war is just beginning. Slobodan Milosevic and his regime will now experience " nights of fire".
The Allies are poised to launch wave after wave of bombers and missiles with a heavy concentration on Belgrade, the capital, which they had sought to avoid in the first week of the war.
High priority will be given to the Serbian leadership and the infrastructure supporting it. President Milosevic's own palace in Belgrade could become a target.
The German defence minister, Rudolph Scharping, warned: "He shouldn't have the feeling that he can murder people at will in Kosovo and remain unmolested himself."
The bombers have hit the Internal Security Institute and the headquarters of the 1st Army, whose senior echelons are said to be Milosevic loyalists, petroleum depots and air defence systems. An attack on a bridge, say the Yugoslav authorities, caused civilian casualties.
Yesterday the first signs of what many analysts see as the inevitable next stage - the use of ground troops, were beginning to emerge.
Getting Slobodan Milosevic to disgorge Kosovo would be a long campaign of attrition needing troop strengths of between 100,000 and 200,000, attack helicopters and heavy armour not at present at the scene.
Such an expedition takes at least six to eight weeks to prepare and would have to be preceded with intense daily air strikes. As Nato military officers repeatedly point out at brief-ings, in the Gulf the land war was preceded by weeks of ferocious bombings and missile attacks to soften the enemy.
But the Foreign Secretary, Robin Cook, has said Nato troops will establish sanctuaries in Macedonia on the Kosovo border for refugees. Camps were being constructed and pounds 10m will be committed to the project.
The Nato secretary-general, Javier Solana, has said action by ground troops may become necessary, and commanders accept that a corridor may have to be established through Kosovo and a safe haven set up on that side of the border as well for the policy to succeed.
The Nato arsenal is building. The Pentagon announced Apache ground attack helicopters were being sent in. They join 13 additional F-117A "Stealth" fighter bombers and the aircraft carrier Theodore Roosevelt, with 50 attack jets.
The safe haven option would be a compromise between depending on air power alone, a policy increasingly seen as discredited, and full-scale intervention, which could cost huge casualties.
But even this limited operation is full of pitfalls. There would be inevitable hostilities, with the hilly, rugged terrain favouring hit-and-run tactics by the Serbs, and with it the sight of body bags going home.
Macedonia's minority Serb government last week announced it would not permit a helicopter attack force in its territory targeting their kith and kin across the border.
If these problems are reconciled, the campaign, according to military analysts, will still take up to three weeks of high-intensity action. The best route into Kosovo would be from Skopje in Macedonia through mountain passes into rolling hills and valleys where Nato armour will have a signal advantage over the Serbs.
But there are five key bridges and if they are destroyed, Nato tanks will face massive difficulties. There are the additional problems of mines laid by retreating Serbs.
The first phase would be heavy tactical air bombardment to take out Serb artillery and anti-aircraft defences. This would secure flight lanes and ground routes. The strikes could come from carriers or Nato bases in Italy and Germany.
The initial probes on the ground would be from special forces, including the SAS, sections of which have already carried out clandestine missions behind the lines to flush out Serb commando units that may have taken up potential ambush positions on the high ground. The special forces will be able to call upon the Apache helicopters from the Air Cavalry and A-10 Thunderbolt aircraft on targets. Search and rescue units would be on stand-by to aid the special forces if needed.
The offensive proper would start with with another wave of bombardment followed by paratroopers and special forces sent further into Kosovo to capture strategic positions, including bridges and the airport outside Pristina.
They would undoubtedly come under fierce fire from Serbs and must hold their ground to allow the main part of the force to fly into the airport on C-130 Hercules transporters with light tanks, armoured cars and light artillery. Scimitar and Sabre light tanks could also be flown into protected areas.
Simultaneously, armoured columns would thrust from Macedonia with Challenger 2 tanks, Scimitars and troop-loaded Warrior armoured personnel carriers under a protective air umbrella.
In the final phase, refugees would be rescued and passed along the corridor to the safe haven on either side of the border.
This would be a vulnerable period with risk of high civilian fatalities if a Serb attack breaks through, unless a masking movement further northwards forces the Yugoslav army to go on the defensive over routes into Belgrade.
After all this had been achieved a strong Nato presence will have to be retained to defend the safe haven from Serbs who will regroup and seek to strike back.
This in itself may lead to a land war by a process of intensifying engagements.Reuse content