I do not believe that Afghanistan was based totally on the US's agenda. Obviously, the US was the fastest to react, being the sole recipient of the devastating 9/11 attacks and having a huge population and region to protect. But other countries could just as easily have been attacked in 9/11 instead of the US, and they still could have been. So they tried to strengthen world security by going into a terrorist hotspot (ever so brain-smashingly stupidly the sole creation of the US government and CIA.) I love how they can make heroes out of the CIA operatives that "fought them damn commies trying to save Afghanistan," while swearing to not rest until they have Bin Laden's head on a stick.
World peacekeeping and international development is still, to be quite blunt, a complete joke. We pop in one place, kill a couple of "bad guys", prop up "the good guys", then flee.
Why not instead, try peacefully negotiating with the party you disagree with? How about you bring troops in under the UN to provide pressure and to act as neutral peacekeepers while you continue to negotiate with the aggressors? Why not build infrastructure for the people that, if schools and hospitals are found disagreeable, could include sewage systems, sustainable energy sources (the types that tend to have a myriad of other uses as well,) roads & rail, and irrigation?
And why not, for god sake's, try not to kill thousands of innocent civilians while you're "Protecting the good ol' American Dream"? Honestly, I'd say that it'd take 20 Taliban to make up for a single civilian casualty, and that's if we should even by trying to wipe out the Taliban. A great many are in fact not religious extremists but citizens who feel they're not being treated fairly. How the hell does it make a shred of sense to go around killing the very unhappy villagepeople that you're trying to make happier? Well I guess that if you killed enough of the really unhappy guys, it'd raise the average, but it'll just make the rest of the people pissed off 'cause their husbands and sons all went and got shot down by Mr. USA.
Let's say your brother's out protesting against some stupid government decision (let's say prorogation of government.) Then, the government cracks down and police arrest hundreds of peaceful protesters, including your brother. What're you gonna do? You're gonna take some action against such an unjust thing. So you go out and protest, but the government comes down again. Now you're in jail. And your son figures that he wants his dad and uncle back, so he goes out and protests... By the end of the month, your jails are going to be jam packed, and there's going to be nobody left to be angry about prorogation, just a bunch of innocent people that were responding to violence locked up in cells.
Perhaps instead of having a big military presence showing off their guns and having a "my tank's gun is so much bigger than your's" contest, we should actually make foreigners seem human. Get more humanitarians out there; teachers, infrastructure workers. Hell, guys that go around villages, knocking on people's doors and saying "SALAM! Tasharafna! Kaya halak?" to everyone they see. I certainly would be a lot more inclined to be nice to a country if I got more than a bunch of burly, armoured men walking around with sunglasses and giving off fake smiles as though their work was a continuous photo op as what their people are like. And if they didn't go around killing my family members by accident and say "We're sorry." with absolutely no emotion whatsoever and only admitting it about a month after the fact.
Don't get me wrong, I think we need to be in Afghanistan. In fact, we need to be in a lot of other places too, including regions closer to home. But the problem is the strategy being employed. In a global world, war can not be waged as it was before, especially against an insurgency. And with a future where basically all the world's conflicts will be insurgencies and constantly changing heterogeneous battles of ideology throughout countries and regions, that strategy needs to be figured out now. It doesn't work to just kill all the bad guys and send money packets to the guy you like for the rest of your life. It won't be stable, and it sure won't create a better world for anyone.