Did the American government employ sex slaves during the Second World War? The newly appointed chairman of Japan’s public broadcasting system apparently thinks so.

In the latest in a string of revisionist statements by conservative leaders in Japan, Katsuto Momii said the “comfort women” system, in which women were coerced into serving in brothels for Japanese soldiers during World War II, “could be found in any nation that was at war.”

“The comfort women system is considered wrong under today’s moral values. But the military comfort women system existed as a reality at that time,” said Momii. “Can we say there were none in Germany or France? It was everywhere in Europe.”...