On a positive note, with enough warning I could drive to Downtown DC pretty quickly to get to Ground zero- for once traffic in that direction would be a breeze…

For example, when contemplating the use of nuclear weapons as purely defensive, or a deterrent, the munitions mix should be chosen to take out large targets, such as cities, (there isn’t much point in hitting a missile silo after it has already fired its missiles. The ideal warheads for this are several high-yield weapons employed in high altitude air bursts. You don’t need to pulverize a city to its component atoms and dig a deep crater, but you can set off a burst at high altitudes to set fires in buildings and vegetation over a wide area. You use several aimed at different parts of town in case the enemy succeeds in partially taking out your second strike force, you still will have a few left to cause unacceptable (although not necessarily total) damage to civilians and property. Low accuracy, robust, simple weapons like this are cheap and can therefore be deployed in large numbers underground, or in submarines, where some are sure to survive even the most devastating enemy first strike. In this way, they are an effective deterrent. In a way, this is even more humane; this Mutually Assured Destruction strategy is meant to be used only if your enemy shoots first. Also, the detonation of air bursts is less likely to kick up lots of fallout, only the bomb casings themselves will contribute radio-isotopes to the fallout, not the huge amounts of neutron-irradiated dust kicked up by a ground burst. It is unlikely any modern society can survive after the destruction of a number of its cities, regardless of how much a civil defense program or backup supply depot system they have. The snake dies when the head is cut off.

On the other hand, a power contemplating a first strike (a sneak attack) will have totally different priorities, and very different strategy and tactics. For a first strike, you will need highly accurate weapons designed to hit hardened or protected targets like missile silos and submarines. Powerful warheads are unnecessary, since you plan to hit very close to your target (within meters!) but you will need many of them (because offensive targets will need to be hit multiple times in case the earlier hit missed or failed. These missiles will be very expensive, since they will need to use highly accurate and shielded weapons, decoys, multiple independently targeted warheads, maneuvering re-entry vehicles, and redundant targeting to ensure as many of the enemy retaliation capability is disabled. On the other hand, the guy who plans to shoot first doesn’t need silos or submarines, right, by the time the enemy knows there’s a war on, the first salvo will already be in the air.

To sum up, the defender needs enough simple, well-protected, cheap, big missiles. The aggressor needs a lot of small, expensive, complex
missiles but he doesn’t need to hide or shelter them. And he needs a strategic defense (ABM) system to stop the relatively small response the enemy’s retaliation will present. “Defensive” measures, like Civil Defense and Star Wars are of little use to the recipient of a first strike, he’s going to get clobbered. Its the aggressor, who knows his enemy can only respond weakly, who can benefit from this. That’s why I put “Defensive” in quotes.

Of course, both strategies are employed by both sides, but a study of their procurement and deployment, and the mix of tactics, will tell you whether they are contemplating going first or not.