In 2007, during French Bastille Day celebrations in which troops from every EU member state marched down the Champs-Elysees, Mr Sarkozy said the EU should construct a unified military.
The Bastille comments followed similar remarks from German Chancellor Angela Merkel in March of the same year on the occasion of the EU's 50th birthday. At the time, she said in an interview that she supported the idea of a unified EU army.
However, the UK, the largest of the EU's big-three military spenders ahead of France and Germany, has until now opposed the idea of a common EU force, arguing that it would unnecessarily duplicate tasks performed by NATO.
According to the Lisbon Treaty, rejected in June by the Irish in a referendum, the North Atlantic alliance "remains the foundation of the collective defence of [EU] members," with NATO always headed by a US general, however.