I disagree with this. The U.S. military has no single conventional opponent that can reasonably oppose it, anywhere in the world. Keep in mind this article is coming out after the U.S. simultaneously engaged in two decade-long wars simultaneously while still maintaining continuous presence in Asia, Europe and with hardly a blip on the economic radar in the U.S. During WW2, the U.S. shifted virtually the entire economy to a war footing, and outproduced land, sea and air vehicles and munitions of several other combined nations. The U.S. spends a remarkably small fraction of GDP on war goods at present, but history shows that when it gears up in one direction, it can rapidly turn into a highly militaristic society.

In fact, the U.S. military is optimized for external operations and force projection, home turf is not the kind of advantage it was throughout history. There is no tactical position on the planet that a conventional military can assume that the U.S. cannot effectively target. Americans have absolute dominion of the skies, with a multi-phased air force that can erode even highly fortified air defense systems. American missiles can be launched from ships, submarines, mobile launchers and so on and can strike, soften or destroy armored stationary armored targets. American armor is so advanced, and numerous, that it can fight in the middle of a chem-bio weapons attack, while on the move, take multiple armor piercing rounds, and still fight. American foot soldiers are heavily armed and armored. They're among the best trained in tactical fighting, and can fight in open battles to urban landscapes equally well.

In unit on unit fights, the American military almost always absolutely dominates. The Officer corps is trained at some of the finest military schools in the world, with lessons on logistics, strategy and tactics that span lessons learned from thousands of years of history. The schools are so good, the other countries send their officers there for training. Americans are pragmatic fighters, without doctrine of fighting to the last man or always pushing ahead. It doesn't waste time training for tough-man parlor tricks. There's minimal shame in retreating because it just means you can fight again tomorrow.

On the flip side, the U.S., despite having huge borders, is a virtual fortress. Two huge oceans means any non-American invader needs to project massive military power around half the planet, something no other country can do. Once here, the U.S. is packed full of military bases with something like more than a million active duty soldiers, most of which are veterans of overseas campaigns -- the U.S. has almost been continuously at war since its founding. There's around another 800,000 reservists. Something like between 30-40% of all Americans have been in the military at one time or another. Beyond that, there's another 70million fit for duty and there are as many guns in America as there are people. This is a military of volunteers, people chose to join.

The problem is that conventional wars aren't what's likely to happen. The U.S. maintains a massive conventional force, but also has decades of practice fighting unconventional wars against guerrilla-style tactics. It's not optimized for it, so it doesn't do it very well, but it's further along that route than virtually anybody else -- for example, American air power now has a non-trivial percentage of unmanned, long-dwell, drones, that are increasingly armed and capable. The need to fight against conventional air forces is dwindling.

Going forward, the U.S. is going towards unmanned drones, either autonomous or piloted from thousands of miles away, exoskeleton and armored enhanced ground troops, autonomous tactical walking ground units, auto-aiming and firing weapons, enhanced mesh sensor networks, directed energy weapons, rail guns, higher precision munitions, hyper-spectral computer vision enhanced vision systems, live tactical coordinating AI, advanced 3d models of entire countries down to cm-level precision, simulation systems that can predict everything from enemy sniper locations to how many GPS satellites you're nav system will be able to see from this position in a city, blocked by these buildings, 12 hours into the future.

The U.S. is conceivably 3-5 generations ahead of everybody else on the planet in terms of technology and techniques and is on a path of bringing to bear this future technology without having to put a single American on foreign soil. Even U.S.-level advanced militaries like Britain and Australia are no longer able to keep up. Hyper-advanced economies like South Korea license 2-generation older fighter planes, which are outfitted with lesser avionics and radar systems.

The U.S. still struggles against asymmetric tactics, but its catching up fast. SOF units are developing tactics and are training specifically to counter asymmetric enemies. A combination of intelligence and precision strikes, theories of human organization and communications, anti-enemy-logistics, anti-improvised, anti-etc. If the U.S. can cover conventional and asymmetric warfare reasonably well, there's no force on the planet that can withstand it, not conceivably in the next few generations.

The rise of other powers is more likely to bring Americans out of the complacency of the 90s, and reinvigorate military development and maintenance, not threaten it.