There is almost always some truth to go along with fiction. It definitely would be interesting to read, and worth shelling out a few bucks...
Here is a quote from the author during an interview:
"The book was extremely difficult to research because many of the
facts were unbelievable, bizarre and took enormous effort to
corroborate. I began by reading most of the mainstream works about Tae
Kwon Do and conducting a couple of crucial interviews (to see if I
could gain access to the deeper stories), then I dove into obscure
sources, including more than 4,000 pages of U.S. Congressional
documents about Koreagate (the scandal that followed Watergate in the
1970s), documents that contained previously classified details about
martial arts leaders and secret-service agents in Tae Kwon Do in the
1960s and 1970s, which was when Tae Kwon Do became as hot as Karate and Kung Fu.
I interviewed some of the pioneers of the art after much of the
research was done interviews that were the most challenging in my
life as an investigative journalist. In once case, I had to interview a
former martial arts assassin. In a second, I needed to corroborate that
a martial arts instructor had been a Korean CIA agent in a highly
publicized presidential kidnapping. In a third, I had to triple-check
that a cult had been involved with Tae Kwon Do. I found at least two
sources, usually three, for every fact"
I'm reminded of another book that was supposed to be true where the writter had inside knowledge of seedy Korean secrets called Race Against Evil by David "Race" Bannon. You should look him up on google to see the results of his labor.