China Strike (M.I.A. Hunter 16) by Stephen Mertz
INTO THE RED ZONE!
Dr. Yu Bin isn't like any other M.I.A. Stone's tried to extract from the nightmare of a Communist prison. Dr. Yu stayed behind at his own request, a heroic volunteer in the undercover war against brutal oppression. Frail in body, Dr. Yu is strong in resolve to not crack under torture - until his sadistic captors turn their threats to his family.
From the underworld of San Francisco's Chinatown to the mean streets of Hong Kong, Stone infiltrates the dark heart of Red China. His men join forces with the infamous 14 K gang - whose loyalty lasts as long as it takes for money to change hands. And the enemy is after them in battalion force. But Stone learned one thing in Vietnam: a determined guerrilla team can pulverize an army regiment..