Walter Satterthwait: The Aegean Affair (USA 1982)

From the Publisher:
HIS PRESENT WAS FULL OF PITFALLS, HIS FUTURE UNCERTAIN, AND HIS UNSAVORY PAST WAS GAINING ON HIM...
Colter had no choice. He had to accept the assignment that would lead to a reunion with his Vietnam "buddy," the infamous Peter Markakis... and to Asporgos, jewel of the Aegean.

Within hours the luxurious island paradise would become a setting for explosive violence. Within days Colter would be plunged into a diabolical battle of wits, torn between his love for a beautiful woman and the demands of a suicidal mission, targeted dead center in the cross fire of a multibillion-dollar drug war.

The stakes were impossibly high. It was a life-or-death gamble. It would take daring, skill, and sheer luck to survive...
THE AEGEAN AFFAIR

Walter Satterthwait: The Aegean Affair. The idyllic island resort masked a deadly secret. Only a man with no choice would meddle in... The Aegean Affair. Dell, ISBN: 0440100763 (May, 1982), 315 p., $2.95.