Why didn't the Cold War get bloody?

[Pat Mustard]

Disclaimer- I've studied very little history in my life; I never even learned anything about the World Wars in school. So correct me if I'm wrong about something

What I'm curious about, maybe from someone who knows history better, why after World War 1 and 2 escalating so severely and nations being so ready to take up arms, the Cold War never actually got violent. It seems the stage was set for the Cold War to really be World War 3, given the fact that the world's major powers were involved and many smaller countries got tied up in it. Yet the world avoided repeating the 50,000,000 casualties of World War 2. What factors ended the large-scale violence between major powers that had been so prevalent in the first half of the century?

Luck, pure and simple. A bear wandering onto a base nearly caused the US to start a nuclear exchange, and the only thing stopping the USSR from responding to Able Archer with saturation nuking was dodgy electronics leading to computers refusing the activation codes.

Edit: the cold war wasn't so bloodless in Korea, Vietnam, Iran, Chile, Angola, Congo (Kinshasha), Greece and many other countries the powers fought over with proxy armies.