President Obama's popularity is high in Germany--the site of one of his largest speeches during the 2008 campaign--but differences with his current host, Chancellor Angela Merkel, are creating tension on his visit. Publicly, the two appeared close as they toured Dresden Friday, with stops at the Buchenwald concentration camp, and the military's Landstuhl hospital planned for later. But disputes over how to address the global economic crisis, what to do with Guantanamo Bay prisoners, and larger questions of Germany's role in the world, are chilling relations with one of America's traditional allies. "They're not angry, they're not anti-Obama or anti-American," a former ambassador to Germany says. "But they're confused by the wave of criticism which has been sent at them by the administration and people close to the administration."