Throwback Thursday - Operation Sulu Sea by Edward S. Aarons

On Throwback Thursday I will bring a brief re-introduction to a book out of print.
Last week it was a serial romance; this week I push back even further, to 1964 with a hard-boiled espionage thriller from Edward S. Aarons, Assignment Sulu Sea. This book was originally published in 1964 and went right to paperback. It was reprinted three more times, all by Fawcett - 1968, 1974, and 1981. It is the 20th book by Aarons featuring CIA agent Sam Durrell. It has a 3.54 star rating on Goodreads.
This novel, like the other 41 in the series, was set outside the U.S. and in the same temporal period as it was written (i.e. the 1960s). So the themes are the Cold War themes of the day. Aarons sold over 23 million books in the Durrell series, rivalling, at the time, Ian Fleming's James Bond novels in popularity. 
Assignment Sulu Sea is short, only 160 pages, so can be read in an evening. Durrell finds himself in a mystery with a missing submarine, friends in unexpected places, murder, and political intrigue in a Pacific island chain. It can be bought for as little as $5.63 on Biblio.