The simple answer is: they didn't. In Rwanda the killing apparatus was set in motion so quickly that people didn't have time to react and offer organized resis

The simple answer is: they didn't. In Rwanda the killing apparatus was set in motion so quickly that people didn't have time to react and offer organized resistance to their neighbors. Only in Bisesero was there meaningful fighting. In Chile enemies of the state were rounded up in the days following the coup and tortured to death. In Argentina people were disappeared. In Spain there were arrests, assassinations and reprisal killings. At Katyn, how were the Poles to know they'd be shot one by one? At Beslan, the attackers preemptively shot anyone perceived as a threat.