Red Dawn (1984) IMDb
A string of briefly outlined events leave the USA politically isolated. The country is then invaded by several communist armies. Some kids from a small Midwestern town turn themselves into guerilla fighters, without training or much information about the war. A downed pilot teaches them a few things, including the extent of nuclear exchange.
Cold War turned hot, action. Often bizarrely political—less heroic Poledouris music would have helped—but sometimes nuanced. The concept is the best thing about it.