This is the difference between responsible and irresponsible chaperones.
Thousands of American kids travel abroad without any problems every year. They are usually well-supervised, and have a chaperone ratio of 1 chap. to 8 kids.
My son's godmother has been taking HS students to France, England, and Italy for 30 years now. She has had minor problems--like a kid who broke a leg--but never once had a child become a crime victim. She is a resposible, wary, alert, and dedicated teacher.
Yep, foreign trips like that can be a once in a lifetime trip for some people. A few years later I was asked to go on one of the trips as a chaperone, but the notice was too short to get away from work. :(