Thirty million children, far from home. Here are three of them.

I have two photos on my desk. The first shows a child, a girl of about 10. She is standing behind an enormous pile of her family’s belongings, which have been tightly packed for a long journey. Her face is blank with uncertainty, but she strikes a bossy pose — one hand on her hip, the other planted firmly against the bundles. Her companions are an older woman, probably her mother, and a little boy — her younger brother? Both look directly at the photographer, Henri Cartier-Bresson, who took this picture in Dessau, as scores of Germans displaced during World War II began returning home. It is 1945. Where has this girl been, and what has she seen?