Britain and France have signed two landmark defense treaties aimed at closer cooperation on nuclear safety and military cooperation. British Prime Minister David Cameron and French President Nicolas Sarkozy signed the treaties in London today.Under the agreements, the two countries will create a joint military expeditionary force of 5,000 troops as well as share aircraft carriers and nuclear test facilities.Cameron called the treaties a new chapter in a long history of cooperation with France, and pointed out that both countries have in recent years deployed troops in the Balkans and Afghanistan. Sarkozy hailed the signings as historic and unprecedented. Both leaders insisted the treaties will not preclude either country from acting independently on military matters. The nuclear component of the agreement calls for scientists from both countries to use research facilities in Valduc in France and in Aldermaston in Britain. British officials say each country will maintain sole possession of any experimental data.