The manga makes the nuclear exchange make much more sense than in the anime. The anime made it seem like Japan was nuked by the United States, which makes no sense. Instead, the US decided to take out China and North Korea. It's still crazy the US would do that, but China and North Korea were clear threats when this manga was made and had limited means to retaliate. American relations with Russia were better at this point and it's unlikely a first strike would actually win against Russia. It's also crazy that Russia decided to dog pile on China. China sends its last nukes to hit Japan for some reason, and the US and Japan work together to try to defend Japan.
