France is back in the Nato fold

President Sarkozy has announced the most radical shake-up in France's defence and security policy for more than 40 years - since 1966 when President De Gaulle hauled France out of the military alliance of Nato as a very Gallic gesture of independence from America.

Sarkozy told 3,000 French officers today that their country will rejoin the integrated military command of Nato, and reform its forces to fight global networked terrorism.

For Europe, Nato and above all Britain, the implications are profound. Britain will now have a full partner in Europe that can slug at the same weight. They are the only two European countries in Nato with the manpower to send a fully fledged armoured division of 30,000 into the field for combat operations - the gold standard from the American point of view.

In Afghanistan in particular, France will now

share a lot of responsibility with British forces - whom it already partners in the Special Forces operation against the al-Qaeda threat along the Pakistan-Afghan border. It also means the UK will share with France top jobs in Nato such as the Deputy Supreme Allied Commander's post - and this will be no bad thing given British overstretch.

One of the main reasons for the reform of the French forces - which includes a cut in troop strength by 47,000 to 224,000 - is cost. France still intends to keep an independent nuclear weapon. Because this takes more than a quarter of the country's entire defence budget, it has to share elsewhere. Fighting terrorists also costs - and there is a desperate need to share intelligence more intensely now with Britain and America.

Sarkozy wants to make France's forces more agile and flexible for fighting the 'wars among the people' of the 21st century. The British will welcome this. As a French student friend used to say, "We French, we Brits, we understand each other - we are enemies from long time!"