Couple notes:

1. I don't like the characterization of "go it alone" because it obviously implies adherence to some kind of extreme that simply isn't represented in reality. No one is shutting down the ports and firing ambassadors; if it were possible to quantify these things (it isn't), reducing global power projection from 100% to 80% is not "going it alone".

2. The true form of "economic largesse" the US has given the rest of the world is Security. Its come at great cost to the country; America has lost ~600,000 souls in conflict in the past 80 years. I'm not saying America has a unique claim to losing lives in battle, Russia and China and others can claim much more devastation, but America is unique in the sense that nearly none she's lost were in her home hemisphere.

9/11 was maybe the only attack since Pearl Harbor that a foreign adversary successfully executed on American soil; but the wars that followed were really a tipping point in American force projection. We'd already been fighting wars in the middle east, then you go back further with Vietnam... America is a country that's spent eighty years chasing the Moral Righteousness it felt when it helped win WW2 for the Allies. The American people are tired of it; her sons and daughters work two jobs, can't afford a home, yet are asked time-and-time again by the latest rich disconnected President to deploy across the world to fight for "Freedom". Or, now, to send a hundred billion in military aid to Ukraine.

I think that's the "clawing back" the poster was talking about: maybe the story of the next century is one where America still projects force globally, but toward the more specific goal of Peace rather than post-WW2-era Western Idealism, and with an expectation of economic cooperation. Money has, after all, been the American God for many decades now.

3. The idea that the rest of the world would simply continue on in the wake of some idealized "US full-on isolationist pull out" is not rooted in reality; and that's part of the reason why this is not happening on the extremes. The US has been a critical force for both War and Peace over the past 80 years. If the US hadn't sent a hundred billion dollars to Ukraine over the past three years, Russia would own the country and share a new, huge border with NATO ally Poland. Implicit and Explicit US security guarantees have stopped China from projecting naval power across Taiwan and other SEA countries. US Support of Israel has... well, the region would look very different if we weren't there, whether there would be more or less war is another debate. My point is: The suggestion that America would lose relatively to the rest of the world in this unrealistic, hypothetical scenario, is not rooted in reality. The far more likely outcome of this unlikely scenario is: War, amongst military peers, the worst and most bloody kind of war, while America enjoys massive oceans, a trillion dollar defensive military, the most economically prosperous natural resources on the planet, and neighbors who could never put up a fight.

No one wins, but America and her western hemisphere allies would lose the least. Fortunately: This is not what America, today, wants. Its not even what the Trump administration wants. Again, a reduction from 100% to 80% is not a "full-on isolationist pull-out".