[B.T.]

First of all: I'd prefer to call it "national stereotypes". We do not see many Asians or "coloured"* people in Germany (At least not as many as in several other countries.).
I can imagine, that this may be different in other countries/armed forces. But I'm not jumping on that train!
The attitude towards people with another skin colour/racial background has never been issued in one of our T2k-sessions. We have two non-caucasian characters in my player group, a black former ballet dancer (PC), and an Amerindian medic, James "Dancing Crow" Travis (NPC). They have been added to add a little flavor to the game, but their background is not a big issue.

I think, national stereotype or prejudice would depent on the situation: It makes a difference, if you (being part of an American unit in Poland) had friendly encounters with people from other NATO forces. They may say:
"All Greeks are >Insert your favorite prejudice on Greeks!<, but Venizelos is pretty cool. He's a real good shooter and never let one of us down! Very hard-working and allways sober!"
Having been in contact with someone over a longer period may change your perception!

But, off course, I use some cliches:
Soviet: Brutal, poorly equipped (even to T2k-standards), determined to do a good job in the eyes of their leaders.
A Soviet unit would not bother to wreak havoc to a cottage or settlement and it's inhabitants, if they think, this action would help their plans.

Polish (military): Hard fighting and professional. In contrast to a lot of other forces, the Polish soldier is aware, that he fights in his own country. He will try to be "frienly" towards civilians, because these are his brethren.

American: This is strange. The players in my group portray Americans. In certain situations the Americans in my game behave like real-life Germans. Given the distribution of Hollywood movies (and American TV shows!), this is not a problem. Just watch TV and you will find a lot of American cliche-types to copy for the game.

Germans: I tend to portray rear echelon types or staff members very bureaucratic. They are more interested in formality or discipline than most other forces. But I think there would not be too much difference in behaviour, if you look at the front line troops.


* No offense intended: I have to admit, I'm very uncertain, how people with black skin are called nowadays. Are they "Afro-American", "coloured", "black"? Hm, I don't know.