You Might Want to Know: Can nuclear weapons ever be “tactical” weapons?
To war planners, a “tactical” nuclear weapon is one that could be used on a battlefield. When it comes to nuclear weapons, the weapons considered “tactical” may today also be called “low-yield” weapons.
The yield of the bomb that destroyed the city of Nagasaki, the equivalent of twenty kilotons of TNT, is now considered “low-yield” and the upper limit of “tactical.” Little Boy, the bomb that destroyed Hiroshima, yielded fifteen kilotons, 25% less than Fat Man, so it too is now “low yield.” Neither Little Boy nor Fat Man was used in a tactical operation, however. Those bombs were dropped on cities, not on battlefields. Some of the people in those cities were soldiers. Most were not. Some in Hiroshima were our soldiers, being held there as prisoners of war. The bombs destroyed hospitals and schools as well as any facilities in those cities of military significance. The destruction of military targets was incidental to the destruction of the cities themselves and those who happened to be in them. At those yields, it couldn’t be otherwise even if you said your target was a “war plant.”
When Bill Clinton was elected, Congress began to require from our presidents a “Nuclear Posture Review.” The United States’ 2018 Nuclear Posture Review has called for us to develop more “tactical” atomic weapons. The Review implicitly recognizes that in most situations our big “strategic” weapons are simply too big to use. For anything. We need the tactical nuclear weapons, the NPR says, so that other countries will believe we will use our nuclear weapons, even, this NPR says, if we ourselves haven’t been attacked with nuclear weapons.
After World War II, we had gotten to work to make nuclear weapons that were smaller and lighter than the bombs used in Hiroshima and Nagasaki. In the Eisenhower years, we designed and deployed, mostly in Europe, lots of “tactical” atomic weapons. Because we imagined that World War III would start with Soviet tanks pouring into Western Europe, hundreds of these “tactical” nuclear weapons were stationed there until the end of the Cold War. President Eisenhower believed that the conventional forces we still had in Europe wouldn’t be able to stop them. Rather than putting in enough conventional forces, President Eisenhower decided to rely on the less expensive “tactical” nuclear weapons. The tactical nuclear weapons would stop them.
We had by then learned how to make nuclear weapons that had a “variable yield,” sometimes called “dial-a-yield.” Now our soldiers could set the yield on the battlefield, just before using the weapon. The W31, produced from 1958 and used on the Honest John surface-to-surface tactical missile we gave to our Army, could yield two-, twenty-, and forty kilotons, two times Nagasaki at the top end. The W45, which we developed in the early 60’s to use in tactical missiles and as a demolition munition, could have yields of 0.5, one-, five-, eight-, ten-, and fifteen kilotons--the yield, at the high end, of the bomb dropped on Hiroshima. The smallest “tactical” warhead we ever produced, the W54, introduced in the early 60’s, weighed around fifty pounds and could yield the equivalent of anywhere from ten to one-thousand tons of TNT. One thousand tons is four hundred Ryder trucks, if you remember that one.
Some of these “tactical” nuclear devices were put into artillery shells, some into short-range missiles, some into depth-charges and torpedoes, some into mines, some into demolition munitions, and some into bombs that could be dropped, not by the bombers of the Strategic Air Command, but by fighter-bomber aircraft. All were intended to support troops on a battlefield, provided the troops you were supporting weren’t too close to the troops that were your target. They would have to be miles away from a W31 that had been set at forty kilotons.
The “tactical” B57 bomb, which we started producing in 1963, could yield from five tons to twenty kilotons, the yield of the Nagasaki bomb. The “tactical” B61 bomb that we began to produce in 1968, which was deliverable by fighter-bombers, could yield from three-hundred tons to three-hundred forty thousand kilotons. Three hundred tons is a low yield for a nuclear bomb, but at least thirty times more than the yield of what had been our biggest conventional strategic bomb in World War II. On the high end, the yield of the B61 is seventeen times Nagasaki. In the 70’s, we developed a warhead for our cruise missiles, the W80, that could yield from five to one-hundred fifty kilotons.
The B61 and the W80 are still in service. For an enemy to know what yield we’d selected for them and whether it was “tactical” or not, they’d have to wait until the warheads exploded. They might not want to wait.
Today, in 2019, we believe Russia has more tactical nuclear weapons in their stockpile than we do. Is this something to worry about? You can see why Russia might think they need tactical weapons. They have been invaded twice in the last two hundred years by European countries coming in from the West. On its eastern border with China, it has had actual shooting battles, even during the Cold War. On its south are Muslim countries with whom they are not always friendly. The Russians might think they need to have the kind of nuclear weapons that could be used against an invading force. That’s exactly why we’d put “tactical” nuclear weapons in Europe during the Cold War.
But there may be a problem with the very idea of a “tactical” nuclear weapon. Ten tons, the smallest possible yield for our smallest nuclear warhead, the W54, is twenty times more than the yield of the largest strategic bomb we had in our arsenal before we developed nuclear weapons.
And consider: even if a W54 is set at its lowest yield of ten tons, what is to prevent the next W54 from being set at ten times that yield, which can quickly be done by the soldiers handling it? And let’s say you use a B57 bomb at the “tactical” yield of the Nagasaki bomb, twenty kilotons: you may want to argue that this use should be seen as merely tactical. The other side might not see it that way.
The B61 we still have in service can be set to yield three-hundred tons, which is well within the current “tactical” range, but also three-hundred and forty-thousand tons, seventeen times more than the “tactical” limit. Here comes one! What do you suppose it has been set to yield?
The writers of the 2018 Nuclear Posture Review said, “We must look reality in the eye and see the world as it is, not as we wish it to be.” That sounds right, though I’m not sure where that leaves the American Dream.
Leaving aside the American Dream, when it comes to nuclear weapons, there’s no clear line between “tactical” and “strategic.” We might wish it were otherwise. But any use of a nuclear weapon would greatly increase the risk that any nuclear weapon would be used. When nuclear weapons come into play, because of the scale of the destruction nuclear weapons can cause, the operating principle would likely become “use it or lose it.” That risk is real . That’s looking reality in the eye.
Is it possible, then, that nuclear weapons useless? That question will be raised in a later posting.
Next: At war in the Cold War/Managing a “tactical” nuclear weapon
next to last sentence should read "Is it possible then that nuclear weapons *are* useless?"
Excellent! It refers to today as 2019. Are you going to bring us up to 2021?