Yet exactly how their return is to be achieved remains mysterious. In the early weeks of the enforced exodus, the Alliance missed its chance to prepare for the commitment of ground troops to expel the Serb militia and install peace-keepers. Since then we have become stuck in a variant of Xeno's paradox: the increased momentum of the bombing, and widening of the targets, seems to carry us ever closer to a final offensive - but never quite close enough for it to be under way.
Modern wars are an accelerated race against time. The longer the delay in achieving victory, the more likely the public is to doubt the wisdom of the entire enterprise, and the more likely coalitions are to fragment.
Britain has been supportive of committing ground troops. But, discussing Kosovo's plight with callers on a radio phone-in recently, I was struck by the signs of ebbing of support for the conflict because it was not achieving its aims quickly enough. The sheer speed of modern life leads us to expect instant results in any undertaking, The appetite for hasty resolution, coupled with boasts - often exaggerated - of the accuracy of weaponry leads us into expecting convenience wars to match convenience food. When the polls begin to reflect this impatience, the politicians panic and look for a way out.
With each accidental hit on a civilian target, feelings intensify that Nato's activities are unjustified. The violence on the other side goes on. But that cannot be, as the Government spokesmen would wish, a total defence against doubt. Nor should it be, in a democracy.
Even those of us who support the intervention and know that unintended casualties are inevitable feel queasy when a bomber makes a fatal mistake. We need to be sure that the good achieved in the process will outweigh the harm done in the process. It is one thing to defend air strikes when you know that they are a preparation for a decisive end to the suffering; it is less encouraging when the West delays in laying out what its ultimate aims are.
Against the wall of noise that accompanies any war, the facts speak sombrely but insistently. Mr Blair has shown himself the most determined leader in Nato when it comes to facing down Milosevic. But we run the risk of ascribing to him powers that he simply does not have. Kosovo is "Blair's war", to rival Maggie's Falklands. The comparison was encouraged by Downing Street in order to strong-arm sceptical Conservative newspapers into supporting the conflict on patriotic grounds. But the Falklands were a British dependency. The battle for them was engaged by British troops only, and the outcome was clear-cut.
Kosovo is essentially President Clinton's war, and one for which he has only a patchy appetite. That is Mr Blair's problem. The two politicians, so closely aligned in many ways, have different instincts about this conflict.
Mr Blair has not sought the Third War or any similar ideological tightrope. From the start, he has behaved like a conviction politician, driven by zeal to restore human rights in a benighted part of Europe. His Christianity doubtless played a part here, too. Mr Clinton started out with the same hopes - remember his stirring injunction to Americans to take out their maps and get personally involved in the fate of Kosovo?
He was foolishly attached, however, to the assumption that Milosevic would cave in at the drone of the first bomber. When it became clear that the Serbian leader would not be so obliging, Mr Clinton's key priority became the avoidance of US casualties. It has not changed since.
At the Nato summit, unrealistic expectations were raised about Britain persuading the US into a ground offensive. This turned out to be a chimera. Within Europe, support for the option is waning.
Chancellor Schroder has no desire for a prolonged conflict, or estrangement from Russia. Effectively, the Germans have already ruled out supporting any escalation of the war, even one that would not involve their own troops. Rudolf Scharping , the Defence Minister, who first whipped up outrage with accounts of concentration camps and comparisons with the Holocaust, has spent the last couple of weeks whipping it down again.
So Germany's announcement that it will take an extra 10,000 refugees, as opposed to Britain's reluctant embrace, is not entirely the product of altruism. By extending its generosity in this way, Bonn is signalling that it wants out of the conflict as early as possible. It is a safe bet that it will push hardest and soonest within the EU for a negotiated settlement, possibly involving the partitioning of Kosovo.
Washington, meanwhile, has rediscovered Russian diplomacy after a gap of some 10 years, with the White House encouraging Viktor Chernomyrdin, Russia's envoy to Serbia, to have another go after the failure of Monday's talks. The Russians have no interest in brokering a solution that reflects badly on the power of the Slav bond. It is difficult to see why Moscow would support an outcome in which Serbia lost control of Kosovo totally. If Moscow is to be part of the solution, then partition is on the cards.
This is the option beloved of those who like tidy, diplomatic solutions and drawing new lines on maps. They forget that it is people and their homes, not abstract bundles of territory, they are dealing with. Worse still, partition rewards the very "ethnic cleansing" the West set out to halt, and ensures that the Kosovo Liberation Army continues to fight. It will extend the conflict into the next century.
The only honest solution is an independent Kosovo, on the model of Slovenia, Croatia and Bosnia. Yugoslavia is dead: buried under Milosevic's nationalist ambitions. Mr Blair, for all his fabled flexibility, knows a bottom line when he sees one; he is aware that anything else would fall short of the principled stand he has made against Serb aggression in Kosovo.
"Our commitment to defeat this policy of `ethnic cleansing' is total," he told the residents of the Macedonian refugee camp, "It is a battle for humanity. It is a just cause." He is right.
Nato carries a moral responsibility to ensure that the final chapter of this blood-and-tear-soaked episode of European history is one that ends by allowing the refugees to return home in safety.
Any outcome in which they are unable to do so, however diplomatically tempting in restoring peace, would be a tawdry end to a grand humanitarian undertaking.Reuse content