No blockade or lack of allies was going to make Japan surrender, they were counting on the fear of an invasion so they could sue for peace on much more agreeable terms. Oh but who cares if a lot of people may have remained enslaved by the Japanese once the war was over, right cRusty?
Plus we wouldn't have all those sweet ass military bases in Japan, like we do now. Imagine that, U.S. forces "occupying" Japan for six decades now, where's the outrage from Generation Outrage?