Britain's Prime Minister Gordon Brown, US President Barack Obama, NATO Secretary General Jaap de Hoop Scheffer and French President Nicolas Sarkozy (L-R) walk after a minute of silence to honour NATO military personnel for service in operational theatres, in Strasbourg, April 4, 2009. The North Atlantic Treaty Organisation (NATO) military alliance is celebrating its 60th anniversary this week at a summit co-hosted by Germany and France. [Agencies] Obama campaigns for European support in Afghan terror fight