This breaks down as soon as you stop looking at abstract rankings and dive into the specific logistic realities of force projection. France and to a lesser extent the UK are reasonably capable, but there's no math that adds up to anything approaching America's capabilities.
So,
$(US) + $(ALLIES) > $(US)
$(ALLIES) - $(US) < $(ALLIES)
Tariffs (check - Smoot Hawley), American isolationism (check - America First), I guess we won't be far from the economic crisis (not checked yet - Great Depression).
At best, the US will slowly turn into Qing China. Unrivalled in its sphere of influence, stagnant and complacent. The US has always had a very strong anti-scientific undercurrent and a lot of it was kept in check by importing foreign elites wholesale (fairly sure the US public school system up to university level is nothing to write home about, on average). If the US turns against foreigners, most of the good ones will stop coming.
But Europeans definitely do not want that and up to a point, that's a good thing, yet Europe still needs a big enough force as a deterrent, and it currently does not have that.
Multipolarity means spheres of influence. That sort of works if a region has an undisputed hegemon. It means war if that title is contests.
Right, the same timeline as AGI and Tesla FSD.
We don't live in the 1920s anymore.
Russia's population is falling and the current war is not helping it. Also the last resources of population import for Russia, Russians in Eastern Europe and Central Asia (+ Central Asians in Central Asia) are drying up. Nobody outside of the former Soviet sphere wants to move to Russia.
Yes, all the European-aligned states you mention should currently be opposed to USA [or at least the fascist regime ruling it], because of the threats to Denmark/Greenland. UK, Aus should be particularly aligned against USA because of the threats to Canada (as part of the UK royalty's commonwealth).
Trusting the post-democracy, post-constitutional USA we find ourselves with is major folly. We might as well climb in bed with Russia.
Based on military ranking:
#5 SK, #6 UK, #7 France, #8 Japan, #9 Turkey, #10 Italy, #11 Brazil, #12 Pakistan, #14 Germany, #15 Israel, #17 Spain, #18 Australia, and if it were allowed to, #20 Ukraine.
Based on economic power: I won't even bother, only China, India, Russia aren't US allies in the top 30 or so, by GDP.
The US was a world police but it wasn't alone. Yes, it was far bigger than all its allies taken separately, but those allies could more than double its power.
What the US is doing now is a tragedy that will unfold over many decades.
[1] Based on https://www.businessinsider.com/most-powerful-militaries-202... (if you have a better ranking, please link it).