U.S. justifications of war on terrorism is nothing but whole truth

Question:
http://uk.answers.yahoo.com/question/index;_ylt=AmcLqJNrTWmXncapfyKEIJMhBgx.;_ylv=3?qid=20130117124226AA28bsx

Why do some Americans believe that U.S. justifications of war on terrorism is nothing but whole truth?

Do they believe so as to give benefit of the doubt or simply for blind loyalty without questioning?

Additional Details

@Jimmy,
Are you suggesting that revenge is the only reason?

Answer: