We should certainly be willing to significantly lower our presence there, or at least consider it.

When it comes to Europe, our presence is wasted money. We're part of NATO, and an invasion of Europe guarantees our involvement no matter what, so whether we maintain a bunch of bases or not isn't incredibly relevant because the invader (in this climate) is totally fucked as soon as they step over the line. 

With Japan... China as it currently stands isn't going to risk the economic damage of a war like that, but I suppose you could make the argument that the relationship could shift at some point in the future. I don't know. I'm not going to say that I know we should pull out of Asia because I don't know this. But I do think that we shouldn't be maintaining military bases based on momentum alone. There needs to be a meaningful threat.