An aggressor needs to know that it will not simply be when he crosses a border or when he attacks to kill that something will happen.

And I'm glad that Kosovo is well on the way now to being a functioning democracy where different ethnic groups can live in peace.

I also said that we wanted to learn the lesson of the Balkans to win not the just the military campaign about Kosovo, but to win the peace as well.

Well, if the NATO countries don't make more of their troops usable and don't get the equipment to get them fast where the action is, then the organisation will suffer and will increasingly become irrelevant.

And most countries are now reducing the number of conscripts and increasing the professionals that are available because they're available on short notice.

What I will remember most from my time in NATO is meeting children in the countries where I've gone to, to Moscow and to Kiev, I've met school children.

But we acted pre-emptively in Kosovo in 1999 to stop Milosevic from doing what he was doing and increasingly doing the ethnic cleansing in a systematic way.

You've got to be able to act when it's necessary to act. And you've got to be able to act where the threat is.

For years, we have heard warnings that Europe needs to contribute more to NATO's capability.

In sum, as we enter the 21st century, the Euro-Atlantic community - North America and Europe together - has to face some tough challenges when it comes to improving our capability.