What exactly are you appalled about? Afghanistan's Taliban government  provided material support for Al Qaeda to invade the US and to kill thousands of people in New York. The Taliban was breaching every human rights law on the planet at the time (you may recall the Taliban blowing up ancient Buddhist statues and stoning women to death in football stadiums). What exactly is it about Afghanistan in 2001 that inspired your better democratic modern sensibilities? Or are you a fan or proponent of austere medieval religious death cults ruling countries. 

Afghanistan deserved to be invaded. Iraq did not. This was Bush's mistake. And Canada, as a signatory to Article 5 of NATO, had to join the US invasion of Afghanistan. It is a requirement under the mutual defence provisions of NATO's Charter. The problem with Afghanistan is that it is hopelessly mired in the ancient superstition of Islam. It will take hundreds of years to shed this black death cult.