The arrival of the first of 8,000 NATO troops in Albania yesterday comes with two very different armies preparing for endgames which they hope will see Serb forces driven out of neighbouring Kosovo.
Both NATO and the rebel Kosovo Liberation Army (KLA) hope the Serbs will at some point in the coming weeks be so weakened by the bombing offensive that they will offer little resistance to ground attacks.
The two armies could hardly be more different: NATO carries the big stick, with massive firepower, but it talks softly. The KLA, by contrast, masks its lack of training and heavy weapons with evocative declarations, claiming it will achieve victory at any price. The KLA units in Albania are led by a commander called Plaiko, or Old Man, whose headquarters is a borrowed apartment in a border village. His first press conference this week saw him explain his strategy simply: "We'll fight and not stop fighting."
Both armies are now building up in Kukes, an Albanian town 20 miles from the Kosovo border. In the sky above, American, French and Italian helicopters thunder by, while on the ground ever-growing numbers of rebel soldiers, in a wide variety of uniforms, wander the streets or lounge in cafes.
NATO leaders have declared that there will be no ground attack into Kosovo because it would need 150,000 men and cost many allied lives. But their own planners contradict this, saying that NATO air power will in the coming weeks not only decimate the tanks and guns of the Serbs, but probably destroy the will of the remaining infantry to fight.
Alliance planners think under these conditions even a single armoured column, thrust from Kukes across the border with a screen of air cover in front and perhaps helicopter-borne troops making secondary attacks, will be enough to see Serb forces flee.
"They have 30,000 troops, but many of these are police," said one Western military observer in Kukes.
The KLA is making its own plans on the assumption that NATO's bombing will "level the playing-field" between their force and that of the Serbs. The KLA has a similar number of troops to the Serbians, now getting rudimentary training in camps along the Kosovo-Albanian border.
Most of these troops are poorly trained and have little more than machine-guns. But one commander told The Irish Times that when they attack across the mountains, they will have the advantage of knowing the terrain and of having higher motivation.
A KLA spokesman interviewed by phone at the headquarters in Geneva said units inside Kosovo itself have stabilised their lines in a series of enclaves despite being short of food and ammunition. Commanders say one unit has even launched an attack against the Serb-held town of Jakovo.
It is likely that the success of these enclaves in holding out is because the Serbs cannot concentrate armour to attack them without the risk that NATO jets, as they did earlier this week, will blast the entire force.
The KLA, in fact, is like a slightly built boxer waiting in one corner of the ring, while in the other his much bigger opponent is being pelted with rocks by the spectators.
The KLA has made much publicly of supposed collaboration with NATO, after alliance jets destroyed four Serb tanks as they moved on rebel positions near the central town of Malisevo. But despite such incidents, in which KLA commanders call on NATO strikes via satellite phone links, the alliance is likely to stop short of full co-operation.
They will draw the line because KLA help is unnecessary and secondly, because NATO politicians want to preserve at least the figleaf of neutrality in this conflict.
The alliance's original aim in going to war was to force Serbia not just to halt suppression but also to agree to a peace plan that, while giving Kosovo self-government, would leave it within Serbia. Despite the "ethnic cleansings" and massacres, NATO insists that this aim remains, with its briefing officers rather optimistically declaring that when the hostilities are finished Albanians and Serbs can live together again.
The war aims of the KLA are different. Plaiko also said this week that it was now impossible to support the plan that left Kosovo within Serbia, despite the KLA's earlier signing of such an agreement hammered out at the French chateau of Rambouillet in February. "Rambouillet is dead. Things have moved far beyond that. We must have independence," said Plaiko.
A clash of interests between the KLA and NATO is possible in the coming weeks
should the two armies each go racing into Kosovo with the Serbs in retreat. A more immediate and daunting obstacle is now threatening to derail both their plans: the presence in Kosovo of hundreds of thousands of Albanian civilians.
The Serb halt to its "ethnic cleansing" of Kosovo this week has left the Belgrade regime with the option of using these unarmed Albanians as "human sandbags" either to deter air attacks on vital targets or to halt a ground offensive in its tracks.