The one thing common to war and violence is hostility. War is hostility on a large scale, over a long duration of time. It may involve violence, it may involve cold shouldering, it may involve economic sanctions, it may involve social alienation. read more
Mutual disdain between political parties and use of violence by them against each other does not constitute as war. To be classified as a war, the conflict must be widespread, intentional, and declared. read more
Conflicts are generally violent encounters, however a war is a state/condition between two governments that are usually declared by the government/state in an official capacity (formal declaration of war, don't think we - the US - has seen official declaration since 1945).. read more