The United Nations' expert on the Palestinian territories said Thursday there should be an investigation into possible war crimes committed during Israel's 22-day Gaza offensive. Richard Falk, a Princeton University professor, said the scale of the attack “against an essentially defenseless population” may have breached international humanitarian law. “To lock people into a war zone is something that evokes the worst kind of international memories of the Warsaw Ghetto, and sieges that occur unintentionally during a period of wartime,” Falk, who is Jewish, said in reference to the starvation and murder of Warsaw's Jews by Nazi Germany in World War Two. During the offensive, the U.N.'s refugee chief, Antonio Guterres, complained that it was the only conflict in the world where civilians did not have the right to seek safety in another state.