Remember the phrase "don't poke the bear"? Well the bear has gotten a lot bigger while the sleeping giant has shrunk to the, well more like a sleeping pill. The US is no longer the power it once was and the people don't know half of what their government has been doing all these years.
America, Russia and China control their regions.
America is the most powerful region in the west.
China and Russia are the most powerful in the east. Unless Africa and South America get themselves together, reject globalism and build their own empires, there will only be a big 3 for a long time.
America's military power is still unchallenged. Unfortunately, we are wasting it on poorly armed, poorly trained ground troops in the middle of the desert. We don't need F-35's or AC-130's to fight these people. They are basically just target practice.
I doubt America, China and Russia will ever fight each other directly. If they did - it would quickly degenerate into a nuclear war.