Assignation in Algeria — John Lee

Assignation in Algeria -- Brian Douglas returns, heading for North Africa after his lady love disappears with a disliked competitor. He follows her to Oran, into the bleak Saharan desert, and finally to an encampment where she is held, discovering a major missile conspiracy against the Sixth Fleet. A Russian spy and an Arab named Tewfik help him thwart it. Published in 1971 by Walker, and in four languages.