I don't see why he'd use nukes in this conflict, or think it will lead to WW3, but the hardening of battle lines and failure to negotiate (blame either side you want) means any fantasies about disarmament and reducing the number of warheads we have pointed at one another with agreements like SALT are up in smoke. Which means the chance for accidental or preemptive launch in the future have gone up drastically. Get out of the city.