Any conflict with Russia or China would involve casualties that make 6K dead in Iraq and Afghanistan over 12 years pale in comparison. We would be looking at casualty numbers like that in hours, maybe days, not years of conflict.
The Chinese are way behind in several critical areas one being numbers of 5th gen airplanes. They are learning as a nation, about independent R&D and high rate production. They and the Russians are flying and testing prototypes of challenge airplanes. Typically they would be years from full scale production yet.
Russia is over rated in almost every area, a scenario reminiscent of the bomber and missile gaps of the cold war. Russian hardware is crap, their air to air fighting doctrine is crap. They would have an apparent short success but that would be because they would start with the initiative.
The whole premis that the DoD is the cause behind the air superority power curve is also a myth. The dim congress of the 90's and millenium killed F-22 production limiting the USAF to 187 jets when we should have close to 500. If we had that many F-22s right now, the F-35 program would have had an entirely different complexion.
I was at an Army base recently. Within 5 minutes, I saw a half dozen grossly overweight women in uniform, with 2 wearing sneakers with their ACU.
If a real shooting war pops up, I don't know if we could mobilize.
The advantage of being the aggressor is that you get to pick when the fight starts.
This means that you can focus on your economy until it's good enough to produce the weapons you need to win.
Russian hardware is crap when it’s used by third rate armies like Saddams.