Which power was best prepared for war in 1939?

Which major power was best prepared for war in 1939?

Probably Britain, though its forces were the most geographically dispersed and it did not know where war would begin.

Britain was probably the best-prepared major power in 1939. Its forces were also the most geographically dispersed. Britain could not be certain where the war would begin and therefore could not treat readiness as the same thing as concentration at one expected front. The exchange distinguishes overall preparation from the ability to mass forces for a known opening campaign.