The correct answer is - Cold War.
The rivalry between the two biggest powerhouses in the world, the United States and the Soviet Union, was known as the Cold War. The Cold War period is a period of great rivalry, tension, threats, arms race, space race, technological race, pretty much direct and intense competition in everything in order to prove the world, and the opponent, that they are the better one, the strongest one.
Luckily, this 46 year long period, even though with few situations being right on the edge, didn't resulted in another war, because if it did, it was going to be much worse than the World War II by far.