I'd say the foreign powers aren't exactly monolithic, they're giant institutions being carried out by local people of varying abilities and inclinations.
I like your custom threat moves, Jason, but I think Danny's 100% correct about this point as well. Definitely something to keep in mind.
I definitely thought about Angola and "Mwaantaangaand" as potentially cool concepts to play out using Apocalypse World rules. The Angolan civil war is nuts because of Castro sending all the Cuban troops over and then the US, China, and Soviet Union providing aid and advisors to various sides, so I'd encounter similar issues there and would probably make custom threat moves but try to treat most instances as fundamentally local. You don't really encounter fundamental US interests (or anyone else's) directly in Angola, at least back then. But man, thinking of the Selous Scouts as a AW threat makes so much sense. Scary shit.
Also, if I was ever going to play Cold City again, AW is definitely the first place I'd look when rewriting that game from the bottom up.