Ted Carpenter has a good piece today in The National Interest: Trump Can Fix the Defects in US Foreign Policy. Whether the Trump team will be smart enough to do this or not remains to be seen, but they at least are not drawn from the same establishment Washington foreign policy teams that have so poorly advised preceding presidents, Republican and Democrat alike, apparently suffering from "groupthink". And Trump certainly has made it clear he and his team are rethinking American foreign policy.
Carpenter identifies, correctly I think, three main defects in America foreign policy since the end of World War II.
1. Threat inflation - the tendency for American foreign policy experts to see a new Hitler in every tinpot dictator who arises, and a potential world war in every minor expansionist move by these tinpot dictators, and to over-react as if each one were an existential threat to the US. A few may be a real threat to us; most are not.
2. An inability to set priorities - as Frederick the Great said,"He who defends everything defends nothing." The US has extensive and expensive security commitments all around the globe, and it is costing us a fortune that could be better spent on other things. We don't seem to be able to distinguish between "nice to have" and "necessary". Nor do we seem to be able to do "tough love" and tell, for example, Europe, with an economy bigger than ours, that they need to step up to the plate and take on their own defense, rather than relying on us for almost everything.
3. An inability to make cost-benefit or risk-reward calculations. As Carpenter says, we don't seem to be able to distinguish between desirable outcomes and essential ones. We have spent 15 years in an expensive series of wars in the Middle East with no discernible improvement in the situation - and it is not the least bit clear why it should have mattered that much to us.
I recommend reading the whole article, because Carpenter makes a good defense for his thesis.