That stuff is overrated - apologizing for history. Please.
I don't feel Japan, as a modern nation, should have to make a formal apology for something their country did 60 years ago, under completely different leadership.
I will suggest that the neighbors are against Japan rearming because Japan is a real country (not headed by some crackpot dictator) and a US ally, which makes them a potential superpower. Considering China's current and ongoing human rights violations, it would stun me if they were complaining that the Japanese hadn't apologized for WWII.