Okay, seriously? Germany committed the same amount of atrocities, and where are we now? Do we have restrictions on our right to have and deploy armed forces? And why don't we? Following your logic, we should still be barred from those things, same way Japan is.
Of course, there's a difference. During the cold war, Germany's industrial strength was too valuable to not use it on military expansion, and since the US needed a large Tank force to stop or delay a WarPac advance into western Europe, the Bundeswehr was born.
Then there was the Reunion back in '89, which directly caused us to regain full sovereignty.
What did the Japanese do that was so much worse that they still have to have restrictions on their ability to act as they please 20 years on?