LONDON // Britain and France agreed on Tuesday to set up a joint military force and share equipment and nuclear missile research centres in what Prime Minister David Cameron hailed as a new chapter in their relations.
Treaties signed by French President Nicolas Sarkozy and Cameron pave the way for close military cooperation between the neighbours, western Europe's biggest defence spenders.
The NATO allies, Europe's only nuclear powers, have a centuries-old history of military rivalry and, more recently, have differed sharply over issues such as the Iraq war.
Their new partnership is driven by the desire to maintain cutting-edge military capabilities while at the same time reducing defence spending to rein in big budget deficits.
The treaties create the potential for the British and French defence industries to work together in areas such as unmanned aerial vehicles or drones, equipment for nuclear submarines and military satellites. The allies will work towards a "single European prime contractor" to develop a series of new missiles.
France and Britain agreed to set up a joint force numbering around 9,000 soldiers with air and sea support, which could assemble as needed to take part in NATO, European Union, United Nations or bilateral operations.
"Today, we open a new chapter in a long history of cooperation on defence and security between Britain and France," Cameron said.
Cameron's government announced two weeks ago it was cutting Britain's 37 billion pound ($59.4 billion) defence budget by 8 percent in real terms over the next four years to help rein in a record peacetime budget deficit.
France's aircraft carrier Charles de Gaulle and a British carrier that is being built will be made compatible so that each country could fly its planes off the other's ship. The ultimate aim is to have one carrier at sea at all times.
The treaty has provoked fears in the British press that an effective French veto on the use of the aircraft carrier could prevent Britain sending it to defend the Falklands Islands in the event of a repeat of the 1982 war with Argentina.
Asked about this scenario, Sarkozy said if Britain faced a major crisis "my first reaction would be to try to understand why such close allies are in such serious crisis, and how we could help them."
Cameron, seeking to placate eurosceptics in his party suspicious of greater European integration, said the agreement was "not ... about weakening or pooling British or French sovereignty, this is not about a European army."
He said he expected Washington to welcome the agreement.
The two countries agreed to share nuclear warhead research and simulation centres.
London and Paris expect to sign a contract with Airbus by the end of 2011 to support both countries' future fleet of A400M military transport planes. a summit declaration said.
Ian Godden, chairman of Britain's ADS (Aerospace, Defence and Security) trade group, welcomed the treaty. "The conditions for cooperating with French industry have never been better."
France's Dassault Aviation AVMD.PA and Britain's BAE Systems BAES.L have made a joint proposal to develop unmanned planes for the two nations, defence sources said.
Defence Equipment Minister Peter Luff said separately that Britain planned to publish a policy document next spring setting out its defence industrial policy for the next five years.