Throughout the decade, Churchill watched Germany building up its military and armaments, and called for Britain to build up its own armaments in kind. He believed that Britain had to rearm in order to deter Germany from starting a war. Yes, he criticized the appeasement policy at Munich, but that was already 1938. However, it was Churchill’s “early and often” warnings about Germany’s military buildup that made him the obvious choice to replace Chamberlain after the invasion of Poland. When they finally declared war after Poland was invaded, Britain realized how exposed they were due to inadequate defenses. This was a result of not rearming, not a result of allowing Hitler to walk into Czechoslovakia.

Churchill wasn't out of Government, he was still an MP, he sat on the backbench calling for action, while the Conservatives, who hadn't really trusted him since he defected to the Liberal Party, even though he had been the post war Chancellor of the Exchequer, ignored him. He had been badly politically damaged by the disastrous return to the Gold Standard and thereafter, the Abdication crisis. He remarks repeatedly in his autobigraphy and his History of the Second World War that he called for early rearmament and the enforcement of international law, especially vis a vis Germany.