Britain's Prime Minister David Cameron (front L) bows during a ceremony commemorating the 100th anniversary of World War I in Ypres, June 26, 2014. Also pictured are (back L-R) Poland's Prime Minister Donald Tusk, Sweden's Prime Minister Fredrik Reinfeldt, German Chancellor Angela Merkel, Cyprus' President Nicos Anastasiades, Slovenia's President Borut Pahor and France's President Francois Hollande. [Photo/Agencies]