Back then every area claimed to be near a primary target due to some reasoning or another. Some of the stated reasons were more plausible than others, but the reality is there were far more of these claims than there could be primary targets.
The USSR peaked at nearly 40,000 nuclear weapons, one for every 10,000 people in the US with 15,000 to spare for allies.
Cold War Joke: Q: How can you tell if a nuclear explosion is strategic or tactical? A: It is tactical if it explodes in Germany.
Remember, towns in Germany average 7kt apart.