It is normal that the terrorists should be punished for what they did. What happened in New York City, Washington DC, and Shanksville, Pennsylvania on September 11, 2001, was horrible. Hijacking four planes, crashing two of them into the two high-rise buildings of the World Trade Centre and another one into the Pentagon was complete no-sense. Fortunately the terrorists in the fourth plane were overrun by, or had problems with the passengers, and it crashed in rural Pennsylvania, avoiding another bigger disaster, probably in Washington DC.
Unfortunately, as usual when their own people are involved, the Americans
really believe that what happened to them is unique, and that no other country
suffered such a disaster. Moreover, their President, his administration,
and followers, tried to get the maximum political advantage out of it for
their own image and interest.