from what I've read in this thread, it seems we don't want to convert too much to COIN warfare, or we'll be unable to face a regular foe with regular armies. So, the big question is how many COIN special trained people do we need? Could we do something simple like convert one of our regular infantry divisions into specialized COIN warfare experts, or is that not enough? If we need more, could we do something else simple like just add one or more divisions of special COIN troopers to the roster (granted, it may be hard to recruit that many more people, and it would add to the military budget)? IMO, we could afford to reduce the regular army a little (not by any huge amounts) so that we can have specialized COIN experts; it does seem to be the main kind of war we'll be fighting in the near future.
As for whether the USA is ready to face another regular military power... it's going to be hard to say until we actually do so. Our equipment performed well enough in Iraq, although they were a minor foe at best. People both laud and condemn our carrier forces, predicting they'll be swamped with missiles or subs (people tend to forget that the USN has a rather good sub force of it's own, whose main goal is ASW); I doubt that it would be that clear cut, simply because naval warfare is so chancy...