I wonder if the US might be "re-running" the "long decline" of the British empire (1890s through WW II)??
Supposedly (and I'm not an expert on this), the period beginning after 1890 was one where Britain was living as a RENTIER on their capital investments overseas and not so much as the "workshop of the world" --- as they were being subjected to tremendous competition from the Germans and the Americans --- the Germans were more technologically advanced and rapidly cutting into British export markets (except, perhaps in India and other parts of the "empire") while the US was closing off its domestic market both because of tariffs but even more importantly by the rapid expansion of US manufacturing.
(there is even a view that beginning in the 1890s Britain suffered from a slow motiion "great depression" which I think is exaggerated).
Then along comes WW I and by the time that war is over, the US has supplanted Britain as the world's top creditor --- (that was how the Dawes Plan of how to keep German reparations money flowing worked -- US lent to Germany who paid the allies, etc. round and round till the depression post 1929).
The Us moved from creditor to debtor nation long ago and China has been penetrating the US market for decades (since the 1980s?) ---
Finance has come to dominate US capitalists' profit possibilities and that plays a role in reducing competitiveness in goods production ---
So there are some parallels ....
No way to figure out how "slow" the ABSOLUTE US decline will be --- but the relative decline has been going on for quite some time ...