There is another writer with a French Name like Andre De Borchgrave or something who also has good sources in intelligence. he often collaborates with another writer. (Larry someone?)
Leon Uris’ book Topaz was also fiction based on fact about a real French spy in NATO who worked for the Russians. He got out of prison and recently had an interview where he professed that he regretted nothing.
Perhaps you’re thinking of American Arnaud de Borchgrave (educated in the UK and served with the Royal Navy) and Robert Moss (’The Spike’, 1980).