But the point is that there is (almost) always a middle ground. Reality is binary only if you carefully phrase the question. In most cases saying A or the opposite of A must be true is incorrect, instead you must say that A or everything that is not A must be true.
Saying that we are not going to dominate the world is not the same as saying we are going to surrender it to somebody else. In fact, the odds are that trying to dominate the planet will simply accelerate the speed at which some other country dominates the planet. Dominating the planet is expensive and creates even more enemies then we already have. Eventually we will run out of money and odds are one or more of our enemies will get ahead of us.
Or to put it another way, if you want to claim that history teaches that one country will dominate the planet then you also have to accept that history teaches that dominating the planet will eventually destroy that country. From Rome to Briton, history shows that the effort involved in holding on to that domination was one of the key factors in their eventual failure.
A carefull policy of slective intervention when necissary and effective, but avoiding getting into too many fights and a willingness to abandon fights that can not be won. Combine that with a policy of working with allies to share the burden, both at the UN and by alliance. Done correctly we could balance the need to take care of the worlds problems with the need to avoid getting into fights we don't need to. That is the middle ground that would let us continue to progress without draining our resources.
Jay