Naval.operations in the book seem factually viable to my feeble and aging brain. While I was on a gator (Amphibious Ship) during much of the time, several of the underway period were in the Med. And Yes, we did have interference and violation of the international accepted rules for safe navigation by Soviet naval vessels including "spy ships" AKA, AGIs. The 60s, 70s and 80s were tge era of John Walker, a Navy communications warrant officer, who stole and sold vast amounts of crypto keying material and tech manuals to the Soviets; and I am certain was a cause of piracy of USS PUEBLO by the North Koreans.