PRESIDENT Charles de Gaulle shocked the world when he announced 31 years ago that France was withdrawing from NATO's integrated command. Supreme Headquarters Allied Powers Europe was forced to abandon its offices by the Eiffel Tower for the flatlands of Belgium.

And if anyone doubted de Gaulle's grievances towards the US, his chief of staff then formulated a defence policy which considered the US a potential enemy.

Gen Charles Ailleret called his strategy tous azimuts - an artillery term meaning "all points of the compass - and said that France might train the nuclear warheads of its force de frappe on America as well as the Soviet Union.

France long ago abandoned all pretence of targeting the US. Under President Jacques Chirac, it has been on the verge of returning to NATO's integrated military command. In the December 1996 Nuremburg declaration, Mr Chirac even recognised the fundamental role of the US in the defence of Europe.

But as NATO prepares to admit new members from the former eastern bloc, the old tension between Paris and Washington has resurfaced. They agree on eastern expansion, but France's public demands for greater European influence within NATO endanger its full reintegration.

Despite his dramatic gesture, de Gaulle never renounced France's signature of the 1949 North Atlantic Treaty. NATO learned to live with France's awkward position of adhering to the alliance without participating in its military command.

The history of subsequent French defence policy has been one of gradual return to NATO.

"France isn't integrated, but it's as if it were," Mr Frederic Bozo of the French Institute for International Affairs (IFRI) said. "The co-operation is so good that the rest of NATO has very little to gain by accepting French conditions for its return. When it mattered - in the Gulf War and in former Yugoslavia - France's status made no difference."

In December 1995, Mr Chirac announced that France would resume participation in NATO inter-governmental meetings. It was taken for granted that Paris would soon return to the integrated military command.

But Mr Chirac made clear that he wanted to rejoin a changed organisation - one in which Europeans were more equally represented. Like an estranged spouse who talks about coming home, Paris began imposing conditions.

"The old NATO was a Cold War institution, totally dominated by the US since 1949," Mr Bozo said. "What France wants is a new NATO. It's not a question of coming back to the conjugal home. It's about founding a new home altogether."

The June 1996 Atlantic Council meeting in Berlin decided that a "European identity" should be encouraged within NATO. The US grudgingly accepted.

Paris suggested that the position of Supreme Allied Commander Europe - always held by an American general - could be given to a European. The idea horrified the Europeans almost as much as it did the Americans.

MR Chirac then wrote to President Clinton proposing that the second echelon regional commands be reserved for Europeans.

The northern and central commands did not pose a problem, since these were traditionally held by Europeans. But when France said the Europeans must have the southern command in Naples - home to the US 6th fleet and headquarters for Balkan, Mediterranean and Middle Eastern operations - the US emphatically rejected the idea.

The dispute festered for six months. That the then US Secretary of State, Mr Warren Christopher, and the French Foreign Minister, Mr Herve de Charette, detested one another did not help.

When Mr Christopher's successor, Mrs Madeleine Albright, visited Paris on February 17th Mr Chirac told her that France would stay out of NATO's integrated structure until or unless the US compromised on the southern command.

Yet despite the apparent finality of Mr Chirac's statement, diplomats say there is a new impetus on both sides to find a solution before the NATO summit in Madrid next July. France proposed splitting the southern command into "functional" and "territorial" commands, the former American, the latter European.

This too was rejected. For the first time, however, Washington made counter-offers of talks on shared responsibility, the creation of a Mediterranean rapid reaction force led by a European, even the possibility of putting the western Mediterranean under European command while keeping the crucial eastern Mediterranean for the US.

In contrast, Franco-American relations over NATO expansion to the east are trouble-free. Mr Chirac is an enthusiastic proponent of both EU and NATO expansion.

France shares in the NATO consensus that the Czech Republic, Hungary and Poland should be admitted, and Mr Chirac has also said that France "will do everything possible" to further Romania's application.

French insistence that Europe play a greater role was again evident when the government proposed a summit to be attended by France, Britain, Germany, the US and Russia to discuss expansion before the Madrid NATO summit in July. The US responded coldly.

But if next month's summit between the US and Russian leaders fails, the French proposal could provide Washington with a face-saving way of resolving differences with Russia over NATO expansion. The onus for failure, or credit for success, would then be shared by the Europeans.