The Soviet leader, Nikita Khrushchev, had already annoyed Mao by criticizing Stalin, whom Mao regarded as one of the great figures of Communist history. If even Stalin could be purged, Mao could be challenged, too.

No independent historian doubts that tens of millions died during the Great Leap Forward, but the exact numbers, and how one reconciles them, have remained matters of debate. The overall trend, though, has been to raise the figure, despite pushback from Communist Party revisionists and a few Western sympathizers.