This is basically an old war-game from the '80s for an invasion of the USA by a foreign-power (Soviets, aliens, etc.).
Now, thinking of the movie, "Red-Dawn" and specifically, of a limited nuclear-war in which the USA is actually invaded.
What I am thinking of thus far is,
1. A Soviet invasion of the USA.
2. Limited Nukes.
3. American-Resistance force.
4. Large numbers of Central and South Americans recruited / drafted (by pro-Soviet Central and South American governments).
5. Pro-USA governments in South-America having trouble lacking USA's support.
6. A mass Soviet relocation of some of its ethnic-groups to the occupied territories of the USA.
7. Extreme American militias acting in defense of America and of Nationalist-culture (white-supremacists) and even persecution of non-White Americans (Mostly Blacks and Hispanics).
This has probably been talked about before. Thoughts?