What is the main conflict in A Man Called Intrepid: The Secret War by William Stevenson?

A Man Called Intrepid, by William Stevenson, is the fascinating story of William Stephenson and his British Intelligence that functioned out of New York during World War II. Stephenson was code named Intrepid as was his operation, the British Security Coordination, which remained based in New York until September 1945.The allied war effort was at stake.