My position is straight forward.
The US dominance of the international order was at its highest right after the fall of the USSR.
Unsurprisingly, it hasn't been able to maintain the same level of dominance, even if it remains clearly the most powerful player on the scene.
My position is that it hasn't had to.
US policy was always based on the idea of fighting 2 major regional conflicts at once while maintaining the current operational tempo (which is now just North Korea). But as time has moved on, the axises that pose a that to the US has declined. NATO has grown, the Rio Pact has grown, ties with India and Oceania have grown... The US has more military alliances now than it did then.
There are only 2 potential MRCs for the US to consider. If we take them at their absolute possible biggest, it's a unified Sino-Russian conflict involving North Korea and a conflict involving the Indian subcontinent, but the Indian subcontinent is unlikely to unify given the tensions there and ongoing US-India counter-Chinese relations. Pakistan is more likely to ally with China, but it's also weaker than India.
So really if the US can handle a China/Russia/Pakistan/North Korean alliance, it's set. And given that China has no official alliances and is now starting to distance itself militarily from Russia, even that seems unlikely.
Not to mention a generational technological advantage particularly in aviation (which is the most critical aspect of a modern military as I've explained before and which encompasses more than just aircraft; it's actually the vast majority of US military planning).
Let's not forget Iraq had the 4th largest military in the world at the time of the invasion. To this day only 5 militaries, one of them being the US, are that size or bigger. And it had what was, at the time, current-generation Russian equipment. But the US utterly destroyed it's ability to wage war on anyone in days, and completely dismantled it's entire military in just over a month. Even now, only China, India, Russia and North Korea are that big or bigger. Given Russia's performance and knowing how behind North Korea is, those stronger counter-Chinese ties between the US and India really start to become relevant.
The biggest threat to the US military right now is the GOP. Aside from them destroying it from within, the US military is as capable now compared to the state of the world as it was when the iron curtain came down.
That's my 2 cents anyway. I don't understand what you mean when you say it's "dominance at the international order" isn't what it was.