I always get a kick out my students when they come back from the United States and exclaim, "Wow! Americans are so friendly!" Of course, what they really mean is, "Wow! No one even tried to kill us!"

These students usually go to America on a school trip, which is preceded by information sessions in which students assemble, pay money and are issued informational pamphlets and bulletproof vests. Short of group suicide, their trip is bound to be a success.

One student asked me before her trip, "If America is so dangerous, why don't Americans just move to another country?"