One by one, the Free Nations had fallen, until finally America too was under the heel of the invader. Now the only hope resides in a mountain redoubt where six men work in secret on a plan to rock the planet. . . .
The basic premise is: the USA has been invaded by "PanAsians," and the government effectively destroyed. Having subjugated India, the "PanAsians" know how to tie down the USA--lots of labor camps, citizen registration and public executions as punishment for any rebellion. But they also have learned not to interfere with their subjects' religion(s). One small military base, a research laboratory, has escaped destruction; luckily the plucky soldiers have an able commander and lots of technology the invaders simply can't match.
From there, it's just a matter of time. The reader gets to watch how these men build a movement, screw with the "PanAsian" leadership, and eventually free the USA. Of course the technology is hokey and the dialog can be a bit offensive, but it's realistic (yeah, I think slurs are allowable if they're marching your family off to the labor camps). This book was written in 1949 and reflects some of the paranoia that Heinlein later gave voice to in Expanded Universe.
But, it's a fun, quick read and if you like Heinlein, you'll probably like it. It's no classic, but not every book can be.
America is conquered by a limited nuclear attack and then invaded by Asian that Heinlein refers to as Panasaians, which is probably meant to refer to China. Considering the growing threat the China represents in the 21st century this book is actually far-sighted and revlevant to the times we live in today.
Heinlein reveals a unique insight into the cultural divide that the world faces today, and threat of the "Clash of Civilizations" that we must deal with in the 21st century.
In ways the SIXTH COLUMN is like the movie, "Red Dawn," and has the quality of a good old-fashion war movie. If you like your books politically correct - then stay away from it. But if you enjoy a good read, then Heinlein's SIXTH COLUMN is for you.
The worst book I ever read.