Why did britain, france and us not stop fascism during the 1930s?

No one saw it as a threat to freedom. The reason why is because foreign relations at the time was passive after the First World War. No one wanted to start ww2 with Germany which was becoming a superpower at the time through national socialism. After Germany advanced into Poland in WW2 Britain and France declared war in 1939. The United States didn’t join the war until the homeland was attacked by Japan in 1941.