Given the size of ancient empires, that seems like a dubious claim. America struggles to win battles in small areas despite having massive technological advantages. I do like the thought exercise of Genghis and Caesar being told by Joe Biden that their armies will never be capable of what his is.
I'm pointedly comparing absolute apples to apples and not scaling for historical time in my statement. We are not ahead of our near peers like the greats of history were above all others at their moment.
We got trucks, planes, ships, etc.
The endless stream of slaves to move equipment and willingness for legions of men to die along the way would still get destroyed by the fact that I can air lift or ship a small nation worth of equipment on a whim and drop it just about anywhere on the globe as a matter of standard course.
I don't know if that's necessarily true. Historically when a military is outmatched, they focus on attacking supply lines.
The US Army is the liberty ship of soldiering. It ain't pretty, but its constant and good enough at this moment in time where China or others with an endless supply of human fodder would be successful in the slog only at their borders. Deploying that man power farther out is greatly limited.
Given that very specific situation, China and America would probably be about it. At that point it's just a war of attrition.
Kind of what I'm getting at and Russia has shown interesting things I never knew about like their inability to efficiently transport beyond their borders due to rail focus and nonstandard rail gauges. It's kind of beautiful actually. Russian artillery and tanks would be highly effective against soldiering and convoys coming into their country, but fall the fuck apart at their border due to all the nuances of their planning. Despite their invading another country at this very minute, it lends credibility to the claim that Russia is really only a defensive country, if only due to their shitty plans.
America was supposed to have learned that in Vietnam, and Russia in Afghanistan, but both forces continue to make the same mistake.
Don't worry, not a peep here. We invading? We will rock the shit out of the entry and then wonderfully fuck up the cointel and nation building. We are good at tech and logistics. But even right now we are undergoing a shift of traditional hierarchy to teams of teams because of our weakness against asymmetric unflagged networks like Al Qaeda and al Shabab that operate without a single head to cut off.