Demonstrating for PeaceHolding torches, some 3,500 people form the peace sign in Heroes Square in central Budapest, the capital of Hungary, in 2006. The rally marked the third anniversary of the U.S.-led invasion of Iraq. Millions long for peace, but history and current events suggest that bloody conflicts will continue. Yet Europeans have cause for cautious optimism: despite episodes of intense violence and suffering, since 1945 wars have been localized, cataclysmic catastrophes like World Wars I and II have been averted, and Europe has become a world leader in the push for human rights. (© Peter Kollanyi/epa/Corbis)