OTOH, US did just this year lose its longest war and it was against Afghanistan. I rely on this closer event. Granted, admitting the loss there was the first step in road to recovery.
The US military generally has a very "meh" track record.
As for sheer numbers of troops, the US doesn't have the capability to actually outfit, support, and deploy anywhere near a million troops in, for example, the middle east.
It's also not the first time a highly motivated group of rebels won a guerrilla conflict in Afghanistan. The USSR fought a 9 year unsuccessful war in Afghanistan too, if you don't recall, after probably helping destabilize and overthrow the government; the current Taliban leadership grew out of factions of the mujahideen that ousted the Soviets back in the 1980s.
I'm no military expert, but it does seem like the US is not geared towards massive troop deployments right now. I've always thought that's because the expectation is that we won't have a massive troop war like WW1/WW2 again.
“Probably”?
And that's despite massive and direct US support to the Mujahideen, which the US didn't have to worry about.
Afghanistan was a winnable war. The way to win the war was, from the outset, to build a strong state that is fairly self-sufficient and motivated to defend itself, without too much corruption. The US military wasn't able to do that. At every turn they were ineffective in rooting out corruption and moral decay, didn't have anywhere near a workable vision for a path out of the Afghan disaster, and lacked the ability to implement a stable political system.
I agree that the US isn't geared towards massive troop deployments. That's why it's absurd to trot out troop numbers as the person I was replying to did.