Berlin ? First, President Bush snubbed Chancellor Gerhard Schroeder. Now a Tennessee high school has called off an exchange with German students.

More than a dozen students from Hamburg’s Sachsenweg School were to depart next Tuesday until their hosts suggested they stay home rather than bring “anti-American feeling,” said Sachsenweg English teacher Jutta Kuehn. The German agency that coordinates educational exchanges said other programs also have been called off.

Despite efforts by officials including the American ambassador to Germany to play down such incidents, the cancelation was another indication that the disagreement over Schroeder’s antiwar stand is beginning to strain German-American friendship at its heart.

The bond is rooted in Germans’ gratitude for American aid rebuilding after World War II, defending West Germany during the Cold War and consenting to German reunification in 1990.

Germans remember their own history of aggression and destruction in two world wars, followed by their decades of insecurity on the Cold War front lines.

In the case of Iraq, they worry about a humanitarian disaster and say they haven’t seen enough evidence that the threat posed by Saddam Hussein justifies military action now.

But flag-burning and comparisons between Bush and Adolf Hitler during antiwar protests this week prompted German President Johannes Rau to appeal to demonstrators not to “stir hate against America.”

These are just the sort of misunderstandings that 30 years of educational and cultural exchanges between the United States and Germany are meant to bridge, said Sabina Margalit, the executive director of the German American Partnership Program in New York.

To confront German stereotypes, the German Foreign Ministry grants about $1 million a year to student exchange programs. This year some 6,000 students from each country are to participate in exchanges, recovering to pre-Sept. 11 levels.

Gottfried Boettger, an official at the government agency that coordinates the exchanges, said other programs have been scuttled by war but declined to elaborate.

Kuehn, the teacher, said she could understand Americans who consider the Germans ungrateful. “But it is sad when the kids have to bear the brunt of political events.”