Maybe you don't want an American-trained doctor. Maybe (as you noted) you feel such a doctor eminated from an inferior education system. If you said, "I don't want an American doctor. I want a _________ doctor." Should someone sue or boycott you, or try to make you lose your job, because you feel that way? Suddenly, in that situation, I don't think there would be any furor. People (Americans included) would probably agree that you have the right to feel that way and a right to select your doctor. But, be American and openly reject a doctor trained in any other country . . . outrage.
And, it happens so often like that: Prejudice and discrimination are often only viewed as a problem if directed toward specific groups. Males are generally not one of those groups -- you can say any derogatory thing about the male gender, and its generally accepted. Mind you, you can't disparage BLACK males, as this would be strongly condemned as racism, but just saying "males" are stupid, lazy, abusive, childish, you name it, generally flies. (I work in a largely female-staffed facility, and for several years signs were posted in female staff work areas, and even in classrooms used by both genders, that said "Women are generally smarter than men" and "Grow your own dope -- plant a man" . . and not even the male staff complained about it. We males seemed to acknowledge that this is female-oriented humor in a female-dominated setting, and we didn't take it personally. But, the news is replete with stories about female staff working in male-dominated settings who effectively stop the men from engaging in male-oriented humor and displays of interest. Again, the reality is that male-bashing is OK, but female-bashing (or anything that could be construed as unkind to women) is intolerable and subject to prosecution. Oh, and if you really want to be on safe ground with your comments, make sure to emphasize that the disfavored person is a white male of European decent, Christian, heterosexual and able-bodied. You can practically spit in that latter person's face, and any objection to that will be characterized as delusional whining.