Listen, even if the Japanese sunk ALL USA ships in 1942, the USA would just have a bigger navy than japan in 1948 or something. The Japanese never stood a chance. I don't think people understand but... the USA never fully mobilized during the second world war. What the USA showed was FAR from what the full might of the USA could achieve. I am talking an economy so strong, they could probably push out multiple carriers, dozens of cruisers, 30 destroyers, and a battleship EVERY MONTH. A fully mobilized USA could at that point in time if they truly wanted it, and at the costs of many lives, take over the world itself. Japan would be completely decimated if the war ever was brought to its soil. And pray for their souls if they tried to invade. The USA in the 1940s didn't need to call people to arms. People where already armed. And seeing how the Japanese were basically as evil towards everyone as the nazis were to polish jews, the American people would be fighting back, and at the end of the war (which the USA will have won) They would probably be so pissed at the Japanese, they would decimate the country. They could destroy ALL the culture, destroy even the language itself, and wipe any and all links to pre-war Japan.