Question

Why did western policy of appeasement even though it seemed to encourage more aggression?

Answer 1

To avoid war if possible.

Explanation:

Europe had just finished a devastating war 20 years before where England and France between them had lost over two million young men. That war was recent enough that many still living had vivid memories of the suffering, hardship, and horrors of war, and didn't want a repeat if it was at all possible to avoid it.

It was hoped that by giving in a little to Hitler and the Nazis that they would be satisfied and another war could be avoided.