I DON'T know how these summits look from the outside, but if you are at one it feels like being in a bubble, isolated and detached from the rest of the world, except for the media, who - because they are inside the bubble - are also isolated and detached from the rest of the world.

It's not healthy, for the leaders concerned, the media and above all for our citizens.

Last year at the Thessaloniki EU Summit I had the weirdest experience when swimming in the sea from the front of the main hotel. In the middle distance, along the beach, was a cordon of big 40 foot containers piled about four high. Every so often I heard the odd shout and bang, but I put this down to some exuberance by holiday-makers. It was only later that I was told that there had been some serious disorder on the other side of the container pile.

This week's NATO summit in Istanbul, which lasted from Sunday to Tuesday, was stranger still. Istanbul is Europe's largest city and one of its finest. Straddling either side of the Bosphorus, the waterway between the Mediterranean and Black Seas, it has wonderful views; everywhere you look you are reminded of its extraordinary history, at the crossroads of two continents and two of the world's major religions.

The Christian church as we know it started here. The fourth century Roman emperor Constantine converted to Christianity and moved to the city - then called Byzantium (subsequently called Constantinople after him, and now Istanbul).

What today is the Aya Sophia Mosque was in fact the first great Cathedral of Christianity - the Church of St. Sophia.

When the Muslims took over they added some minarets but scarcely changed the name, so intertwined have been these two religions, especially in this part of the world.

But so attractive is Istanbul that it is usually swarming with tourists in their hundreds of thousands. They may have been there, in what was perfect weather, but I never saw any, at all. So total was the summit bubble that the city, or that part of it from the airport to the main hotel where we all were, was simply closed. No traffic, no one on the streets. Just an eerie quiet (apart of course from police).

How much better it would have been if all the tourists, and the Istanbul residents, had been around. But it does not appear possible for now, or the foreseeable future. It comes down to one word - security.

With the Heads of State and Government, and Foreign Ministers from 50 countries the Turkish Government had to take no chances. Our own Consulate in the city had been bombed last November, along with bombs the week before against two synagogues. Almost 60 died then. Smaller scale bombs were let off before the Summit started, and one about an hour before we left.

The problem is this, however. The security is of course necessary. We live in a dangerous world, and personally I am not up for taking foolhardy risks about my own safety, still less about others!

But NATO, like the EU, is there to defend the free world, and to extend it. Yet there we are in a gilded cage, no more able to meet or directly to communicate with the citizens on whose behalf we are there than the old Sultan of the Ottoman-Turkish Empire, who ran a vast territory from Morocco to Iraq, Iran to the Balkans, from well protected palaces and forts.