And what has happened?
Rambouillet is in ashes. Serbia is refusing to budge after 13 days and nights of air raids. Those we pledged to protect are being driven from their homes in the greatest act of depopulation in Europe since 1945. The 12,000 soldiers who were meant to look after the Kosovo Albanians are now doing just that - but in the wrong country, Macedonia. The Serb civilians of Kosovo, whom they were also meant to protect, are now being bombed by us. The destabilisation of the southern Balkans, which we went to war to prevent, is now well underway.
And, instead of admitting the truth, our leaders consistently lie.
At first, we were told that the Serb leader would be forced to end his "ethnic cleansing". The opposite has happened and now we are told - by Robin Cook, no less - that Milosevic will be made to "pay the price", which is not the same thing at all. Nato promised to attack only military targets and, for as long as it thought it could crack the Serb military, that is what it did. But now it is doing just what the Americans did in Iraq - spreading the war to civilian targets, to bridges and electricity stations and factories and refineries, under the spurious excuse that these are also of use to the military. Of course they are - just as roads and railway tracks and water mains are of use to the military. And as we get more desperate, they may well be the next target.
"This was never an operation that was planned for only two or three days," Nato's spokesman James Shea told us on 26 March.
Really? So why were we not told this before we went to war? Why were we not told of the possibility of weeks of air raids and the wholesale abandonment of the Albanian civilian population of Kosovo if Milosevic did not give in? Why do we only now learn about the prospect of a "long war", perhaps lasting four years? And why, for God's sake, did no one - not President Clinton, not Nato's Secretary General Solana, nor Robin Cook, nor General Wesley Clark - realise the bombing must be supported by ground troops?
How on earth did Clark come to believe that the Serbs would give up so easily? Did he mistake the Yugoslav army for the Serb militias of Bosnia? Did he think that bullies are always cowards and will therefore give in? Did he not realise that only a real threat of ground invasion might force Milosevic to agree to the Rambouillet accords in time?
Over the past two weeks, we have been told other lies: that it would have been even worse if Nato had not bombed Serbia - and that we knew Milosevic had planned the total "ethnic cleansing" of the Kosovo Albanian population before we went to war. Clearly, the first statement - from President Clinton himself - is rubbish.
With Serb paramilitaries butchering their way across Kosovo and poised to drive out every last Albanian, it could not possibly be worse. And if we knew that Milosevic had planned this, why did Nato not provide fighting ground troops in those precious weeks following the original Rambouillet conference?
In the past few days, our defence analysts have been hard at work to explain the continued war. Not only is it intended to make Milosevic "pay the price" for his brutality, but any faltering now would damage the credibility of Nato itself. You bet it would. Almost two weeks ago, we thought we had gone to war to save the Kosovo Albanians. Now it turns out that we are at war to save Nato. And yes, yesterday was Nato's 50th birthday, marked by a blazing oil refinery, an electricity station burning itself out in northern Belgrade and hundred of thousands of Kosovo Albanians freezing on the mountainsides of Montenegro, Albania and Macedonia.
We should not be surprised. We asked the Kurds and the Shia Muslims of Iraq to rise up against Saddam Hussein in 1991 and, when they did as they were told, we abandoned them to the torture chambers of Iraq. This time, we asked the Kosovo Albanians to sign the peace accords in Paris and praised the so-called Kosovo Liberation Army (KLA). Now they are on the run, we can do no more than bomb the Serbs from the air.
There was a telling moment last week when a senior RAF officer stood up at Nato's regular briefing to tell journalists that the KLA "has not been defeated" but was "regrouping" in order to "take up the armed struggle" once again. What is this nonsense?
That a Nato officer should seek to support the KLA in such a way proved two terrifying things: to the Serbs, that the KLA was a fifth column (and thus worthy only of execution) and, to us, that Nato now regards this ragtag bunch of ill-disciplined ex-Marxists as its foot-soldiers in Kosovo. The substitute army for the Nato soldiers who will not be sent into Serbia.
The Nato briefings become ever more sinister. At each one, a new and ever more ghoulish story is produced for journalists - the mass execution of intellectuals one day, the rape of young women the next, the killing of fathers and sons in front of their families, the setting up of concentration camps. These stories may well turn out to be true - I suspect the truth may be worse - but the effect is pornography-by-press-conference, with spokesman "Jamie" Shea acting as the East End club doorman touting the evening's horror story and his RAF colleague playing the role of manager, promising us that the show will go on.
And so it will until every last Kosovo Albanian has been driven from his home, or until MI5 or the CIA engineer the secession of Montenegro or the overthrow of Milosevic. And all the while, the promises continue: "We shall attack his murderous forces in Kosovo: we shall strike at the nerve centres of his decision-making machine" (British Armed Forces Minister Doug Henderson). Nato is showing "unflinching resolve" in the battle against the "unbelievably brutal actions of Milosevic's special police and army" (Air Marshal Sir John Day).
Tony Blair is suggesting that the Serb leader may face a war crimes indictment. Do they think Milosevic will be frightened by all this? After his supporters killed and raped their way through far more Muslims in Bosnia than they have in Kosovo, we treated him as a peacemaker. He was invited to the Dayton conference, he was regarded by Washington and by the Foreign Office as "a force for stability in the Balkans" (as Saddam was in Iraq after he invaded Iran). Milosevic was one of "our" dictators - or at least a man with whom we could do business.
But now he has joined our list of "beasts" - we remember Saddam and Gaddafi although, oddly, Osama bin Laden has dropped off our Satanic radar screens for the present. We believe Milosevic can be "defanged" or "declawed", or that we can, in the words of the Sun on the first day of the war, "Clobba Slobba".
Alas, history is not like that. Nato thought that within three days of its bombing campaign, it would have 200,000 Serbs on the streets of Belgrade demanding Milosevic's removal. Instead, tens of thousands of Serbs now gather on those streets for daily pop concerts to demonstrate their hatred of Nato.
There are many words to encompass the events of the last 13 days: brutality, vanity, arrogance. But above all, folly is the word that comes to mind. Maybe we will find another persecuted population to "protect" next year.
They had better watch out.