Your guess is correct! See: https://en.wikipedia.org/wiki/Nuclear_fratricide https://en.wikipedia.org/wiki/Nuclear_fratricide Key quote: "It appears that two w

Your guess is correct! See: https://en.wikipedia.org/wiki/Nuclear_fratricide https://en.wikipedia.org/wiki/Nuclear_fratricide Key quote: "It appears that two weapons targeted on a silo must arrive at least ten seconds apart to avoid fratricidal fireball effects, and less than one minute or more than one hour apart to avoid fratricidal nuclear dust cloud effects."