> Wouldn't it be easier to make Afghanistan a 51st state?
That's probably an viable option last century (see: Philippines, Guam, Puerto Rico), but colonialism/imperialism is out of style right now so it would definitely not be easy to do that.
That's a drop in the bucket for a country that's already full of people from all over the world and constantly bragging about its diversity (despite looking very monocultural from the outside looking in).
At least legally, the US had no “rights” over Afghanistan. Afghanistan was not a colony, territory or state of the US. The government was “free” to kick out the US whenever they wanted.
In practice, US foreign policy doesn't recognize international law and never really has.
The US could annex Afghanistan, and apart from the CCP doing a lot of complaining about it (primarily because they want access to Afghanistan's mineral wealth), nothing would happen.
It may have been preferable for the Afghan people, the vast majority of whom prefer a democracy with election processes, and the vast majority of whom are young and mostly know the post-Taliban life under America's watch. It's unfortunate that America threw away its foothold in the region and has created another set of humanitarian crises - and I don't mean just displaced refugees but also women who will be brutally oppressed under Taliban rule.
And let 'em keep their culture and religion locally instead of repossessing them?