Why did the governments of Great Britain, France and the United States

Why did the governments of Great Britain, France and the United States calmly accept the coming of the fascists to power in Italy and Germany?

Fascists in Italy and Nazis in Germany did not initially threaten the colonial and regional power of France and Great Britain. On the contrary, for Paris, London and Washington, they were a barrier against the spread of communism to the west, a guarantee that the Bavarian Soviet Republic and the pro-communist formations in Ireland and Alsace would no longer be reborn. However, this friendship with fascism and National Socialism turned out to be expensive for Europe. By 1938, the communist barrier had itself become a threat.