Code of Honor by Michael Newton
In Book V of The Bureau—Code of Honor—a grim "Cold War" settles in to replace the recent global conflagration, spawning a Red Scare at home and abroad surpassing the postwar paranoia of 1919-20.
Declan O'Hara returns to FBI headquarters from service in Latin America, to find Aloysius Gantt still striving to curry J. Edgar Hoover's favor. Devon Gantt serves the Bureau in Los Angeles until he, too, is recalled to Washington at the peak of the Red-hunting 1950s. Richard Nixon and Joseph McCarthy leave their indelible marks on a country afraid of its own lurking shadows. When President Truman dissolves the wartime OSS, Colby Gantt transfers to its successor, the Central Intelligence Agency, joining in subversion of "dangerous" governments abroad. Ike Sawyer nears mandatory retirement age at the Federal Bureau of Narcotics, but remains determined to make his last years on the job count for something, while son Payton joins the New York City Police Department, beginning a career that parallels his father's early war against black "radicals." As the USSR goes through traumatic changes, climaxed with the death of Joseph Stalin, Leonid Babin pursues his campaign to raise a son who will become a sleeper agent in America and infiltrate the FBI, destroying it from within.
Their courses converge during conflicts in Korea and Indochina, while Greg Jordan and his Syndicate associates plant their flags in Cuba, launching a new age of gambling and drug smuggling into the United States, with incipient warfare brewing inside Cosa Nostra.