AMSTERDAM — On April 30, 1941, a Jewish man here in Amsterdam wrote a desperate letter to an American friend, pleading for help emigrating to the United States.

“U.S.A. is the only country we could go to,” he wrote. “It is for the sake of the children mainly.”

A volunteer found that plea for help in 2005 when she was sorting old World War II refugee files in New York City. It looked like countless other files, until she saw the children’s names.

“Oh my God,” she said, “this is the Anne Frank file.” Along with the letter were many others by Otto Frank, frantically seeking help to flee Nazi persecution and obtain a visa to America, Britain or Cuba — but getting nowhere because of global indifference to Jewish refugees.

We all know that the Frank children were murdered by the Nazis, but what is less known is the way Anne’s fate was sealed by a callous fear of refugees, among the world’s most desperate people.