I've been replaying Fallout 4 lately, reading the lore, and what has always puzzled me is how the US counter-invasion of China was even possible. I mean, correct me if I'm wrong, but doesn't China need complete naval superiority in the Pacific for the invasion of Alaska to be even remotely feasible in the first place? In which case, China would have needed to expunge American forces from East Asia and the Philippines -- assuming they still had bases there -- followed by an occupation of Hawaii.
And no matter how effective power armor was against infantry and tanks, there's no way they could have withstood a barrage of missiles, especially if the Chinese were already deeply entrenched in Alaska. Taking back Anchorage would have been an absolute nightmare, even with power armor. But okay, say the US did expel Chinese forces from Alaska, they would still have needed to destroy the Chinese navy, air force, missile defense systems, and island hop from Hawaii to East Asia. How the hell was that even logistically possible? And we're supposed to believe the US had landed millions of troops on the Chinese mainland within months?
Here's my theory: The counter-invasion never happened. It was all propaganda to keep the population from rebelling. The American military was already stretched thin in its occupation of Canada and Mexico. And it was also mentioned that the Chinese even made it as far as the Canadian Yukon. If that were the case, the Chinese would have logically also bombed all the shipyards on the West Coast along with many other valuable military assets, making the counter-invasion even more implausible.
In Fallout 3, we see Chinese guns littered across the Capital Wasteland, presumably acquired from trading with the NCR. In New Vegas, Veronica, mentioned the Chinese had invented, or were close to inventing, a new type of gun, a gauss rifle, if I recall correctly, that would have rendered power armor useless.
Some redditors stupidly suggested the Chinese walked through Siberia and... swam to Alaska? We know the Soviet Union was on friendly terms with the US, even up till the bombs fell, so we can rule out the possibility of the Soviets aiding the Chinese in any meaningful way. And that brings up another point: If the Soviets were more hostile to the Chinese than to the Americans, why didn't China invade Siberia instead, then? I doubt the Soviets, with a population of around 330 million by the 2060s, would have exhausted all their resources.
Other than that, I suppose there weren't a lot of alternative options to invade for resources: The Middle East, Western Europe, and Israel had already nuked themselves in their conflicts. The same thing probably happened in South Asia between Pakistan and India. Global warming was also likely much worse in the Fallout Universe due to the lack of success in pursuing renewable energy. From that, we can infer that much of Australia, Africa, and Latin America became inhospitable, if not uninhabitable. Even more bizarrely, the PRC was not able to figure out fusion energy while America could? I mean ffs, even in this absurd timeline, the Chinese had stealth suits! They could just steal the technology and reverse engineer it.
Anyways, enough of my rant, here's a screenshot of my settlement at Tenpines Bluff.