Complex sentence: Such a description in a popular novel assumed and relied upon karate being almost unknown in the West; and it linked karate with judo, whereas in reality karate is a distinct art almost unrelated to judo.
Split into simpler sentences: Such a description in a popular novel assumed and relied upon karate being almost unknown in the West. It linked karate with judo, whereas in reality karate is a distinct art almost unrelated to judo.