I don't know what the correct response was to 9/11, but something had to be done. The invasion of Afghanistan wasn't a charitable maneuver--it was America defending itself (and supported by NATO and UN declarations).
Obviously any nation cannot just sit by and let thousands of their citizens get killed.
Clearly their national origin is not relevant. I was born in Moldova, but if I committed terrorism, no one would think blame a nation I have not lived in since I was 2.
I'm not joking.
What if you've all been in Moldova until a year before the attack like the actual terrorists?
I think you mean Hamburg, San Diego and Palm Beach.
"Let thousands get killed"? They already died, it's not like invading Afghanistan was going to stop killings (of Americans, it's not like USA cared about the killing of civilian Afghanis) which were in progress, sure they were probably planning something, but it's not like Al-Qaeda stopped planning even with bombs falling on their heads.
9/11 was the fuckup of the intelligence agencies, but the bloodlust meant that they had to punch back. And Bin Laden picked the right time with arrogant dishonest war hawks running the country, US' reaction to the provocation killed a few thousand more of their own young men and women and burned so much more of their money.
I wonder if it was possible for the US to have a leader that said "Let's reflect why this happened." Sure, go after the people who did it, but to threaten an entire occupying force (in the form of Taliban) to "Give us Bin Laden or we'll bomb you" wasn't that smart. A smarter administration would've done more barking to scare them to somehow give up OBL, or done more intelligence to find him and drone-strike him, and not get into a 20-year quagmire in the country. But intelligence is a long and quiet process, and all the angry citizenry would've complained that the government is being a pussy by not bombing everything that looks foreign and said "Death to America!"...