I would say..
We should counter China / be a counterweight to them, while not really being in opposition to them fundamentally but rather encouraging them to step up in the world the right way (this is actually what US policy is right now, and that's what Japan and the others talk about regarding China, as well)
So, encourage the Chinese to become a manager of globalism through the accepted outlets, UN security council etc. Get China involved in solving regional crisis / peacekeeping.
It's appropriate to be a leader in the world rather than a conquerer -- that's what the USA has been, and so in the future Asia will be one or the other, either a leader or a conquerer. We'd actually rather that be the former.
I guess it's a bit like raising a kid. You have to oppose them at times, yet guide them, then one day when you're old you know they will be in charge and if you raised them right then it will be okay. Hopefully.
We don't have to have a war with China one day -- we just need to channel their "rise" in the right direction.
Other facets of the new American doctrine should be more consensus-based, not being out front all the time anymore. I do have to give Obama credit for doing the right thing on this, such as in Europe. We shouldn't be sending more forces out until the allies are really sure they want them and have been hollering "where's America." Make sure that coalition is really there, make sure a team is really there, AND IT IS NOT JUST US.
We don't ever want another Iraq, we don't ever want allied populations just saying their parliament was tricked by us.
And -- it's also TIME now, for a more consensus based foreign policy.
Europe is ready for it. They're actually more wealthy than we are. It's time they have their own "European Army" to shore up Poland with, rather than the US Army. There's really no reason for American troops to even be in Germany, or so many of them. Nor having so many troops in South Korea, and Japan, and even Australia.
It's time to begin passing the baton. Our regional allies can look to EACH OTHER more, and less to us.
Domestically -- we need to focus a lot more on that. Less foreign policy, more domestic policy.
The direction things are going with this TPP and all that is world governance. That may actually hinder us to move up, to standards more akin to Europe -- we'll fall in that race to the bottom (or a median with Asia), and Europe will fall to. And lose their social benefits and such, too.
And then who knows, maybe Asia will get so rich we'll turn into an Australia then we'd get a bounce out of Chinese buying so much stuff here.
So anyhow, the above is pretty much what American Doctrine is shaping up to be. Not really saying it's what I'd do, but it's one way to go. (the other way is protectionism, which in honesty may not be the best as far as world peace goes, but I do support Sanders' ideas -- maybe there's a middle ground like Germany does)
If I could add anything to the wish list, besides more domestic policy, I'd like to see big things done in space. If everything else went to sh*t at least we could say "look here, American civilization landed on Mars, it landed on the moons of Jupiter, it has colonies taking root in the solar system."
The space stuff is like our civilization's pyramids, and one of our many great achievements. Long after we are gone, the footprints and stars and stripes and placque will still be on the moon.
Space is also that next frontier, and we could move forward quite a bit by being first on that. So don't cede that one to the Chinese.