PARIS - The unrest buffeting France has further undermined the already weakened presidency of Jacques Chirac, but he is far from alone on a continent with pressing problems and few strong leaders to tackle them. Britain, Germany and Italy also have troubled governments, leaving the European Union in limbo as the Bush administration increasingly shows interest in a cohesive Europe to help with difficult diplomatic tasks in the Middle East and elsewhere. "The whole Western world lacks leadership at the moment," said Guillaume Parmentier, director of the French Center on the United States. "I cannot see any leader who can...