And we have been tremendously successful. The last 50 years has been the longest period of unbroken peace in Western Europe for more than 300 years. Our destiny is now so inseparable from that of our European neighbours that it is unthinkable that war could ever again break out between us. But while we have succeeded in securing peace within our borders, we have failed miserably in preventing bloodshed around them.
I travelled to Kosovo three times last year. On each occasion I warned that unless we showed more urgency and resolve in standing up to President Milosevic, then his aggression would continue and the atrocities would escalate.
And so it has tragically proved, with results that we can see for ourselves every night on our television screens. Men, women and children, in their hundreds of thousands, are being driven from their homes for no other reason than their ethnic origin. The looting, the burning, the rape. The systematic murder of thousands of innocent people.
To have stood by and allowed this evil to succeed would have been to acquiesce in genocide. That is why we had to act. And indeed, the strength of purpose shown by the nations of Western Europe over the last two months has been quite without precedent.
But that does not alter the fact that, at almost every stage of this tragedy, we have acted too slowly and uncertainly. Once again we have relied on the willingness of the US to take the lead in enforcing the will of the international community against an evil on our very doorstep.
When the immediate conflict is over, when - as I hope and pray - Milosevic's forces have been removed from Kosovo and the refugees safely returned to their homes, there are three vital things we must do to show that we have learnt the lessons of this tragedy.
First, we need to create an overarching settlement for the Balkan region. It will not be enough just to watch over Kosovo. We must offer all Balkan nations, including Serbia, a place in the family of Europe. And that means offering every one of these nations a pathway towards membership of both Nato and the EU.
The fact is that the Balkans have only ever been at peace when an overarching power has acted as guarantor. First the Ottomans, then the Hapsburgs, then the Communists. The only hope for long-term stability in the region is for Europe to step into that breach.
Second, we must fundamentally reform Nato. Nato has not performed well in Kosovo. Perhaps we should not be surprised. Nato was designed for total war. It has neither the structures, nor the culture, to fight the kind of "diplomatic military operation" we are seeing in Kosovo. But these are the kind of wars I fear that we will have to fight more and more in the future. If Nato is going to cope effectively it will need fundamental restructuring at both the political and the military level.
And the third thing we are going to have to do in Europe is to start taking defence a lot more seriously. Europe has become an economic heavyweight, but it remains a military lightweight.
Despite the fact that we have a population half as large again as the US, we spend just two-thirds as much on our defence, and our ability to deploy forces beyond our borders is just one 10th of America's.
We can't go on relying on Uncle Sam to bail us out every time there's trouble in our back yard. Because one day we're going to call for the cavalry, and the cavalry won't come. There is a desperate need for a Europe- wide defence review, to look at how, by co-ordinating our efforts more closely, we can get better value for money and greater effectiveness for our military.
And yes, this may well mean a review of defence budgets. Too many European countries have been freeloading on defence and defence spending for too long. Spain, for example, spends just 1.3 per cent of its GDP on defence, and Germany and Belgium not much more. This will have to end if we are to have an effective defence capability on our continent, preserving our continent's peace.
Let us be clear. Kosovo has raised the stakes. From here, we are going to be in a very different European order, one that will require a stronger and better organised EU, and a properly resourced common foreign and security policy.