Why was appeasement used against Hitler?

Answer 1

There are multiple reasons:

1. Britain needed more time to rearm before it could fight a war against Nazi Germany. After the First World War the British public was strongly opposed to war, leading to disarmament in the inter-war period. This meant that when Hitler came to power in 1933 the British military was not strong enough to take on Hitler while continuing to defend the British Empire, so appeasement was used to buy time for rearmament.
2. The British government sympathised with some of Germany's grievances. Under the 1919 Treaty of Versailles, Germany had been forced to give up vast areas of territory and had to pay huge sums of money in reparations to the victors of the First World War. Many felt that the terms of the Treaty were excessively harsh, and as a result did not support military action against Germany when they were broken. For instance, the remilitarisation of the Rhineland was expressly forbidden by the Treaty, but when it happened in 1936 people felt that it was not worth fighting over.
3. In the wake of the Great Depression of the early 1930s, economic recovery was seen as more important than foreign policy.
4. It was believed that the threat of economic sanctions imposed by the League of Nations would be enough to deter any potential aggressor, including Nazi Germany.

Answer 2

Because they did not want another world war. WO I devastated Europe, and they believed they could prevent one by appeasing Hitler.

Answer 3

Because the alternative was war - which eventually happened anyway.