The USA declared a formal war on the Taliban regime (and continued to recognise Rabbani as the legal head of state). They successfully defeated the Taliban regime (who were clearly less powerful in military strength.) Beyond that, the USA and UN assisting states reinstituted proper governance, a democratic regime, re-created educational institutions and restored 'order' to the country. This was perhaps one of the most successful anti-terrorism operations at a very large scale. But one must clearly note that this was against a less powerful foe over a country that had little or no industrialisation since the Taliban regime. Further, the Taliban did not possess armored vehicles, but had an outdated cavalry and their only heavy artillery was mobile rocket silos.
There are many issues regarding the casualties of this war, human rights of the POWs captured and delivered to the Northern Alliance by the invading US forces. But these issues are under dispute. Massive humanitarian aid was offered to the Taliban through the UNFP (United Nations Food Program) and Pakistani help (who wanted to relinquish their image as "Taliban supporters.") The United States did not succeed in capturing Osama Bin Laden. However, the operation did reduce the supply of narcotic products available in the International Blackmarket for the period of the attack and sometime thereafter. Many residents are reported to have resumed cultivation of narcotic crops due to poverty and lingering famine.