cold war

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A state of political tension and military rivalry between nations that stops short of full-scale war, especially that which existed between the United States and Soviet Union following World War II.
• noun A state of rivalry and tension between two factions, groups, or individuals that stops short of open, violent confrontation.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A period of hostile relations between rivals where direct open warfare between them is largely undesired and avoided.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a state of political hostility that existed from 1945 until 1990 between countries led by the Soviet Union and countries led by the United States
• noun a state of political hostility between countries using means short of armed warfare