In his book "The Birth of the Palestinian Refugee Problem, 1947—1949" (1988), Morris argues that the 700,000 Palestinians who fled their homes in 1947 left mostly due to Israeli military attacks; fear of impending attacks; and expulsions. He argues that there was no centralised expulsion policy as such, but expulsions were ordered by the Israeli high command as needed. The official position in Israel was that the Palestinians had left voluntarily, or under pressure from Palestinian or other Arab leaders. At the same time, Morris documents atrocities by the Israelis, including cases of rape and torture. The book shows a map of 228 empty Palestinian villages, and attempts to explain why the villagers left. In 41 villages, he writes, the inhabitants were expelled by the IDF; in another 90, residents fled because of attacks on other villages; and in six, they left under instructions from local Palestinian authorities. He was unable to find out why another 46 villages were abandoned.