That and...
1. 500 meter airburst
2. Big CEP (Soviets depended on huge warheads, because their accuracy wasn’t so hot.)
Could go either way- Ten megs yes- but it could miss by miles and miles on the ‘away from you’ side of the target.
Riley, don’t forget, the Russians and the US both had huge numbers of missiles. More than one would have been targeted at NYC just to counter the “missed by a mile” scenario.