GREG BAKER/POOL/AFP via Getty Images
- For decades, the US has been the world's main military superpower.
- But the US faces formidable new threats, and rising global conflict.
- In the wake of the Ukraine war, Russia and China have been growing closer.
For decades, the military might of the US was unchallenged.
After the collapse of the Soviet Union in 1991, the US was the world's only military superpower, with its forces deployed all over the world to defend allies and deter aggression.