(L-R) NATO Secretary General Jaap de Hoop Scheffer, U.S. President Barack Obama, German Chancellor Angela Merkel and French President Nicolas Sarkozy reach France after crossing German-French border bridge, Passerelle Bridge, which connected German city Kehl and French city Strasbourg, on April 4, 2009. Leaders of NATO member states held a symbolic ceremony on the French-German border on Saturday to celebrate the 60th anniversary of the military alliance and the return of France as a full member.[Wu Wei/Xinhua]