Yes, the initial superiority of one military is greater by a large margin and will remain that way for some time to come. But I think it's misleading wording to say it "has room to improve its lead", simply due to the fact that emerging powers are improving a greater rate, and it's economically unreasonable to believe otherwise.
Plus, no individual actor made the decision to plunge their mighty military power into the conflagration that became WWI.
I keep reading articles on the argument that carriers CAN be sunk. One article argued that only a nuclear attack could do it, but its argument was unsubstantiated. Swarm tactics and drone warfare are emerging game-changers in conventional warfare. More than anything, initial phases of WWIII would be missile warfare. Carrier groups can defend against hypersonic, but cannot do so reliably.
Combine this with a risky false impression - that war could be contained regionally. Would the symbolism of sinking a carrier be enough to have the U.S. back out of the contested East Asian theaters?
I can't answer that question, and it worries me that I can't. If the answer was certain either way, war would be less likely. As it stands, I could see certain gambles being both plausible, and terrifyingly dangerous.
That's a very civil way to frame an otherwise bona fide flamewar topic, without ruining it :)
"no individual actor made the decision
to plunge their mighty military power
into the conflagration"
The big wars were really a form of violent economic panic, writ large, and without descalation channels, partly as a component of monarchy, divine right and authoritarian autocracy, but also horrendously aggrivated by profound leaps of technological power, mostly by way of chemistry and industrial scale production of chemicals.
No one knew it would get that bad, that fast, that way. And during a time when royalty simply would not back down from a fight.
There are hot spots and proxy wars right now. If they go sideways, and spill a hot mess in the wrong lap, could an uncontrolled panic open up and let loose a new kind of conflagration we weren't expecting or have never before considered?
That's probably the hardest riddle. How does one anticipate an unexpected, unplanned atrocity?
I think anyone who thinks that inflicting a sharp defeat on the US in the pacific would crush public morale and push it into a negotiated peace would have to be a very poor student of history.
Additionally, the strongest carrier defense against weapons such as this is the size of the ocean, and their short(ish) range. You can't hit what you can't find, and/or what you can't get close too.
This would depend squarely on the context and circumstances. Historical precedents are of little to no relevance here.
That said - * The S-400 is an impressive system. The Russians have so built ~300 of them, and like any system, the soft factors are more important than the paper facts suggest. Training, deployment, doctrine, and strategic/tactical goals would greatly affect the viability of it on any modern battlefield.
* Space Superiority is more than just ASAT capabilities, but its an area that few other countries have ever even attempted, and with the US's dominance in rocket technology (arguably anyway) and high altitude laser platforms, I'm fairly confident it would be a stalemate at best, with even the closest competitor. I would agree its an area of US defense that will need special attention over the next ~10 years.
* Insurgency =/= Great War.
* OIF was heavily supported by carrier based aircraft, and there are exactly zero countries that posses a modern enough navel force to threaten US control of the actual blue water areas. US Submarine technology is decades ahead of everyone else at this point. There are concern developments in this area, but again, we're talking "Great War"
* True point. Wars tend to get people pointed in the same direction though. Especially "Great Wars"
* US pilots put in more seat time than every other country combined. This is a factor that cannot be overstated. Putting 10x the number of the worlds best plane in the air means nothing if the actual operator cannot leverage those tools effectively.
In the end, these are all great points as to why the US has room to improve its lead, but none of them really address the core point which is that the US is currently the undisputed leader in almost every military category, and any "Great War" involving the US would be a very lopsided affair. You're more than welcome to pick your challenger and we can see how long it takes me to make a list twice as long with their problems, although I can't guarantee I'll actually spend the time doing that today :)