> spending more than the next 7 armies on the list ensures that it is
pointless for any other state to even try to challenge U.S. hegemony.
Hmm, I think that's exactly what Vladimir Putin is doing right now. I mean he's pretty explicit about it. Xi's being a bit subtler about it, but he's kind of doing the same thing. Also, it seems like the US kind of lost the last couple of wars it got into, the ones in Iraq, Libya, and Afghanistan, even though Daesh and Libya Dawn don't have US$610B/year budgets.
More to the point, though, when the US military spends US$43 million on a gas station that would cost anyone else US$½ million, it becomes plausible that someone could have a stronger military even head-to-head than your US$610B/year military, even if their budget is, say, US$8B/year. Like, say, Singapore or Algeria. All they'd have to do is be spending their money on things that actually work instead of corruption-driven boondoggles. Wasting money doesn't win wars.
Would the US really lose if it got into a war with Algeria or, more realistically, Iran (who's currently supporting Russia's attacks against Daesh, over US protest)? Hard to say. Depends in part on how much of that US$610B is getting squandered, in part on whether Iran has a plan for shooting down GPS†, stuff like that. Aircraft carriers versus supercavitating torpedoes is going to be an interesting experiment when it happens. I'm glad I won't be on the carrier.
(Might also depend on what happens if the US nukes Singapore, which is after all a mostly-not-subterranean city-state. Would it trigger a global thermonuclear war, obliterating the US?)
> A very plausible explanation is that when the U.S. became unchalleng[e]able after World War II, it became pointless for any European country to cultivate aspirations of global power.
I can't tell whether you haven't heard of the Cold War or you don't realize that Moscow is in Europe. Either way, maybe you shouldn't be starting sentences with "nobody educated on the subject thin[k]s".
† Does this sound implausible? It shouldn't. Iran has had Scuds for 30 years, and it's been making its own for more than 20 years. Iran has been able to launch things into orbit since 2008, and if my calculations are right, you only have to go half as fast as orbital velocity to reach a GPS satellite, and then Kessler Syndrome might take care of the rest. And don't forget, launching into orbit means they can get a radioactive dust cloud or ten thousand individually-guided tungsten lawn darts to a point of their choosing within the US within a few minutes of launch.