"We will continue to pursue this campaign ... We will intensify it ... until these objectives are met," he told 5,000 US military personnel at Spandahlem airbase. But the diplomats are in Germany too, working harder than ever to broker a still improbable peace.
Suddenly, Kosovo has become a twin-track conflict. Clearer weather in the Balkans and the deepening frustration of allied commanders has propelled the airstrikes to new peaks of intensity. Quietly too, preparations gather pace for a ground war that dare not speak its name: the "semi-permissive entry" of Nato forces into a province still defended by heavily weakened Serb forces.
Yesterday General Wesley Clark, Nato's supreme commander, denied a US newspaper report that the alliance had prepared plans to send 60,000 ground troops - double the number of peace-keepers envisaged under the all-but- dead Rambouillet proposals - into Kosovo to finish the job of forcing the Serbs out.
Formally, an opposed land invasion of Kosovo is not on the table. At least half Nato member countries will not countenance the idea, and this week the US Congress more or less forbade Mr Clinton even to entertain it. But after last month's announcement that the Pentagon would update its ground- war assessments, it would be astonishing if some plan along these lines did not lie upon General Clark's desk.
Simultaneously however, the outline of a first diplomatic breakthrough floats tantalisingly on the edge of the horizon. At issue is not a deal between President Slobodan Milosevic and the allies, who publicly insist on his capitulation to Nato's five demands - but an agreement in principle between the major Western powers and Russia which would permit a first draft settlement to the crisis approved by the UN.
In short, pressure is mounting on all participants. On the West bear pressures of time and public opinion, as it wonders how to bring an end to a war conceived of the noblest humanitarian motives but whose conduct has thus far been a series of strategic errors. But Mr Milosevic too is under a pressure not betrayed in the almost uncanny serenity of his public appearances.
The pressure does not just derive from the bombs and missiles delivered by an ever larger Nato strike force, about to be augmented by 24 F-18 fighter-bombers operating out of Hungary, the only Nato member to share a border with Yugoslavia. It amounts to a round- the-clock bombing war, including lower-level attacks which Nato says are at last starting to hit Serb tanks and other military targets dispersed across Kosovo itself.
But the Mr Milosevic faces a subtler threat as well: intensifying diplomatic contacts between Russia and Western powers which could lead to a deal ratified by the UN Security Council and, as such, impossible for him to resist, whether he approved it or not.
Hence his new hints that he might after all be willing to make concessions on what is the biggest obstacle in the way of a diplomatic deal: the shape of the future peace-keeping force in Kosovo. Now, Belgrade implies, it accepts after all one that is lightly armed rather than completely unarmed. It might, some Yugoslav spokesmen suggest, even contain troops from Nato countries which have not taken part in the bombing campaign, as well as a strong Russian contingent.
Now this is a distant cry from the alliance's demand of a strongly armed force with a "core" provided by the main Nato powers, commanded by a British general and endowed with a single command structure, controlled by Nato. But inch by inch the two sides are edging closer across the miles which separate them.
If Mr Milosevic has moved, then so, fractionally, have the allies, who would be prepared to do without any explicit reference to Nato in the document establishing the force, as long as it was understood that Nato would be running the show. "If the Russians are moving towards the sort of force we want," one senior British diplomat asked yesterday, "Is that such a big price to pay?"
He was, however, begging the crucial question: whether the Russians (whose Kosovo envoy Viktor Chernomyrdin has been scurrying between Belgrade, Moscow, and Washington in recent days) really are now talking a similar language to the West - or whether they are simply trying to save Mr Milosevic's skin.
A key pointer will come today, when for the first time since the air strikes started on 24 March, the foreign ministers of the G-8 group of Russia and the seven major Western powers meet in Bonn, with a reasonable chance of finding enough common ground to permit a UN resolution, enunciating at least the principles of solution.
"There still some loose ends to be tied up before we have an agreed G- 8 statement," the diplomat acknowledged. "But if it all comes out well on Thursday, the next step could be a resolution."
But principles are one thing. The Devil, as every diplomat knows, lies in a host of details.
The biggest single sticking- point remains the proposed international contingent, where Moscow's preference, for an armed but circumscribed force, falls uneasily between the demands of Belgrade and Nato's proclaimed minimum requirements.
But there are others: notably the political arrangements for a post-conflict Kosovo (which Belgrade and Moscow fear could become a de facto Nato protectorate) and terms of a Serb withdrawal. Will the pull-out have to start before the bombing stops - or will there be a pause to test Mr Milosevic's intentions, as Mr Clinton fleetingly seemed to hint at the weekend? Or, as a Belgrade foreign-ministry spokesman defiantly proclaimed yesterday, only when Nato troops have left neighbouring Macedonia and Albania? The Russians would moreover like a few Yugoslav soldiers to remain (perhaps as border guards), as symbol that Kosovo remains juridically part of Yugoslavia. The allies say all must go: anything less and the 700,000 ethnic Albanians driven from their homeland will not feel it is safe to go home.
So the calendar presses. If the air war does not bring Mr Milosevic to his knees first, the planners reckon it will take two months to assemble a land force to move into a "semi-permissive" Kosovo.
Perhaps, as some think, the very brandishing of the threat would induce him to submit. But the practical deadline is the end of July. Assuming some opposition on the ground, there would not be time to clear the province and restore the essentials of basic life before winter arrived.
In other words, the refugees would face another year in exile and abroad. In the Kosovo tragedy, that is perhaps the moral watershed facing the West.Reuse content