Two of Nato's most respected retired generals will issue today a stinging indictment of European military capabilities, arguing that unless the continent pools its defence resources it may be unable to meet mounting security risks, which includeinternational terrorism.

Retired General Joseph Ralston, the American officer who headed Nato until 2003, and retired General Klaus Naumann, Germany's former chief of defence and head of Nato's military committee, argue that European leaders have "lacked the political will" to improve military capabilities.