What is appeasement? And why was it taken up?

The dictionary explananation for appeasement is the act of appeasing (as by acceding to the demands of). But today we mostly think of it as being a cowardice way to look at something or not standing up for something you know is right.

In the 1930's appeasement was the policy both the leaders of France and Britain at the time believed was the right course of action. Communism was uprising in Russia and in Germany Adolph Hitler was in charge. It was a hard time to be a leader and to know what was right for your country it was also a hard time to stand up for your beliefs when all anyone wanted was peace.

The policy of appeasement was pursued in the 1930's mostly...