The United States took military action against the Taliban due to the attacks on the World Trade Center in 2001 by al Qaeda. Osama bin Laden was determined to have had connections to the movement (however tenuous or extremist they may have been) and the movement itself oftentimes encouraged hostilities against Western states due to their century-long period of interference in Middle Eastern affairs.
The Nazis used the theory of evolution as justification for their persecution of the Jewish people. In their mind, Jewish people were "corrupting" the non-Jewish bloodstream. This is what led to the reprehensible eugenics movement.
Washington means that the citizens have had a bit too much trust in the U.S. government without considering that while we have freed ourselves from the British, there is still a chance that this government could also become corrupt under the hands of the wrong American leaders.
