Japan's war timing and the inevitability of US intervention

Was 1941 Japan's optimal moment to attack, and could it have avoided war with the United States?

Waiting would have improved readiness, but any Japanese attack on European Pacific possessions was likely to bring in the United States, while sanctions and domestic politics made retreat difficult.

Japan's force development would have benefited from waiting until roughly 1942, while most major naval powers had originally expected a mid-1940s conflict. An earlier war also left the industrial and logistical depth intended to support those fleets incomplete. Yet attacking European possessions in the Pacific was unlikely to remain separate from the United States, which regarded the region as its strategic sphere. Previous defeats by Soviet forces and the domestic loss of face involved in accepting American sanctions further narrowed Japan's practical choices without making its aggression inevitable or bloodless.