&gt;How likely is it for a random insurance agent who likes to play Harpoon to write dramatization of war plans, and then get the type of access that Clancy had?<p>Tom Clancy was from and hung out around the Baltimore-Washington metro area, home of the CIA (VA), NSA (MD), DoD (VA), FBI (DC), NGA (VA), NRO (VA), State Department (DC), DIA (DC), and a whole host of military bases and installations.<p>His native Baltimore is relatively close to the NSA HQ at Ft. Meade, the naval academy in Annapolis, and the Aberdeen proving grounds. Just sticking to Baltimore and its environs it&#x27;s likely he would have met many military personnel and folks in the intelligence world.<p>Having lived in the DC metro area for a few years, I certainly find it within the realm of possibility that someone such as Clancy would have met these kinds of people. It&#x27;s hard to miss them here given the insane number of driveways with armed guards and no signs. Get a few sailors and intelligence officers drunk, take notes, and piece things together over the years. There&#x27;s a whole bunch of resources to research military equipment and procedures, and a lot of this stuff was in print back in ye olden days too, so one could ask intelligent questions.<p>It wouldn&#x27;t surprise me if, after his financial success, the Feds did provide some sort of assistance considering his support of the military and intelligence agencies. It would also not surprise me if said agencies didn&#x27;t like him for revealing certain things; he was after all talked to by the FBI.