One of the cold war authors, back in the late 70s early 80s wrote a book wherein the Soviets had a flagpole company that supplied poles to locations, govt installations, bases all over the US. They were installing mini nukes in the ornamental balls at the tops. When enough were in place thay would set them all off at once. Really scary story for its sheer simplicity.
Strategic Air Command used to send out a case of books every month to the underground ICBM Launch Control Centers. That book was in one of those cases and one Alert I didn't want to study for my Masters degree so I read that book. IIRC the ending was unsettling.