A “terrible, racist, authoritarian, eugenics-inflected yellow peril novel”, as Cory Doctorow wrote. Or racist dreck, as i would say.

That said, i amused myself a bit while hate-reading this with trying to work out who the evil, evil invaders are. These “Pan-Asians” ar Chinese and Japanese, that hav been turned into Communists by the Soviet Union, that they conquered, or something.
If yu don’t believe the racism: the invaders are just called “yellow monkeys” a lot. And so on.
Ah, and the Americans don’t even try to learn the language. In the end the underground army of thousands, maybe tens of thousands has exactly one translator. The language is described as “meaningless singsong”. W T F.
Oh, and because there is exactly one Asian-American in the story, they arn’t important. Just shoot any Asian yu see. Dto. African-Americans. Their “basic weapon” magically kills “Mon­go­lians” and spares “Caucasians”. As everybody knows, only Whites are Real True Americans. F⸺ck this.
Btw. from the Caucasus it is about half as far to Mongolia as it is to the USA. Those two terms for the “races” is as silly as talking about human races at all. They don’t exist.