Barry Mark Eisler (born 1964) is a best-selling American novelist. He is the author of two thriller series, the first featuring anti-hero John Rain, a half-Japanese, half-American former soldier turned freelance assassin, and a second featuring black ops soldier Ben Treven. Eisler also writes about politics and language on his blog Heart of the Matter, and at the blogs , Firedoglake, The Huffington Post, MichaelMoore.com, The Smirking Chimp, and Truthout.