Preventive war

Preventive war is when a country or group attacks another country or group even though they haven't done anything to them yet. It's like a warning that they are going to do something bad, so the other country or group responds by attacking first. It's like a preventative measure so that the other country or group can't do anything bad first. Preventive war is something that isn't looked upon very kindly because it doesn't allow the other country or group to defend themselves.