>I have read often that most U.S. congress members have a thing against EVER having U.S. troops under the command of non-American officers.

This is one of those areas that opens a lot of debate. Here's an article that explains (some) of the problems involved with this (and is one reason why some people strongly object to U.S. forces being under the command of non-U.S. officers):

http://www.ibiblio.org/jwsnyder/wisdom/pdd25.html