Anticipating war with Japan required earlier readiness

The Atlantic meeting took place against repeated Anglo-Japanese confrontations and intelligence about Japanese preparations. The reconstruction here has British planners expecting trouble around January 1942, while both Britain and the United States anticipated a war sometime in 1942 without knowing exactly when. That uncertainty mattered even if the estimate was broadly close. Preparation in late 1941 would give forces and arrangements time to settle before the expected fighting. The planning argument distinguishes an estimated outbreak date from the earlier date at which forces need to be ready.