Totally out of topic, but I highly recommend it ...
(Not technically a spoiler) I really liked the parallel betweens the bad guys' language, which was manipulative to the extreme, and the good guys' language, which was of course less extreme but still contained deceiving vocabulary
(i.e. Babel 17 is critiqued because the good guys are called "who are invading", yet the bad guys are themselves called "invaders" in English ...)