The non-use of nuclear weapons has been a phenomenon of the past 70 years. Since the atomic strikes on Hiroshima and Nagasaki, no nuclear weapons have been fired in anger despite massive stockpiles, hair-trigger alerts, and the nuclearization of every weapon from ICBMs to 155mm artillery. This peculiar behavior has been analyzed and rationalized over years, giving rise to theories concerning escalation spirals, limited nuclear war, mutually assured destruction and disarmament.
What these theories still fail to explain is why a nuclear power, when faced with a weaker opponent who cannot effectively retaliate against nuclear use would not use nuclear weapons when such use would not result in overly serious collateral damage or nuclear retaliation. Such an omission would be the use of the Mark 4 or 7 in Korea, or the any one of the low-yield weapons the U.S had stockpiled by Vietnam or Desert Storm.
In his book The Strategy of Conflict, Schelling argued this distinction between nuclear and conventional is arbitrary, but the threshold provides a focal point that has been implicitly accepted. Humans have in essence determined that nuclear weapons are not part of the normal chain of escalation. They are a class apart, not because they are more destructive than an equivalent tonnage of conventional bombs, but because they are nuclear.
In this insight, I believe Schelling provides the explanation, but an implicit warning as well. The non-use of nuclear weapons is based on a tacit agreement, one that implies it not acceptable to use nuclear weapons against non-nuclear states, even against purely military targets. In game theory terms, this agreement amounts to a utility maximizing focal point in international relations.
I agree. We have a barrier that is almost universally recognized. Doomed to coordination and cooperation to avoid oblivion, fearing escalation and another world war, the world’s nuclear weapons states have held to this point rigidly. Nuclear weapons were used in only a single conflict and never since. Even smaller, tactical weapons have never been employed even though they were and are available.
Even when conventional capabilities fall short the answer is usually to create a new conventional capability rather than use nuclear weapons. Evidence of this can be seen in the development of weapons like the MOP and MOAB, which were created to do what tactical nuclear bombs like the B61-11 do already. They are made to destroy large troop formations and attack deeply buried bunkers that would otherwise impervious to conventional weapons. The point of these two programs was (in a sense) to create a usable weapon that had the capabilities of a small nuke without being nuclear. The Russian FOAB serves a similar purpose.
Destruction of the focal point
This focal point has existed for decades, but there is always a danger that this implicit agreement could be torn up by a rogue actor who has no qualms about using nuclear weapons, or believes their use is somehow justified in a non-existential crisis. Recently such concerns have focused President Trump and the crisis with North Korea.
I have written extensively on North Korea’s nuclear and missile program and the basic conclusion I have come to is that our hubris, inaction, inept diplomacy and fumbling have led to a DPRK with the means to deliver a 150 to 300 kiloton thermonuclear warhead to the continental United States and no means to disarm them through diplomacy.
Due to some combination of ethnocentrism, hubris, and willful ignorance, many in the foreign policy, intelligence and military communities have somehow convinced themselves that there is a viable military option to solve the North Korean “problem” (as it is framed in American thinking.) Of course, as Jeffrey Lewis noted: A war is only preemptive if it happens before a country obtains nuclear arms. If not, “It’s just a plain old nuclear war.”
Theoretically, the United States does possess the means to “win” a nuclear war against North Korea. North Korea has no advanced early warning or second strike capability. We have the capability to disarm the regime through a nuclear strike on Kim’s C3 and nuclear launch facilities.
After the dust has cleared the couple million Koreans who would perish in the during the attacks and ensuing chaos, along with the devastation nuclear use would bring, it also would destroy the current focal point and help legitimize nuclear weapons as a normal means of conducting warfare.
I believe that this is the most important consequence and one which is often ignored. Here we are not talking about the short to mid-term diplomatic or strategic picture but one of the implicit status of nuclear weapons in human hands in the long term. If the equilibrium is destroyed by a nation conducting a nuclear strike where will the new focal point be?
The rules of the game now change. There is no longer a tacit agreement between the nations of the world because one has gone off the deep end and actually used a nuclear weapon. With the nuclear threshold breached neither side would be able to immediately determine what is acceptable.
What can and cannot be nuked before the final red line is crossed and the strategic forces are employed? If the United States drops 10 low-yield B-61 nuclear bombs on North Korea can Pakistan and India do the same if war breaks out? What if a coup throws Pakistan into turmoil and India, citing the previous American strike, launches a bolt from the blue attack on Pakistan?
While nuclear war would be devastating in the short term, the long-term effects could be even more disturbing. After being used, nuclear weapons will shed some of their special status, not just in that one conflict but all conflicts thereafter. It’s not just bravado anymore.
If the United States attacks the DPRK it will send the message that nuclear weapons are not special and are liable to be used in any future conflict. The global focal point will no longer exist as it did. This is not to say that that nuclear states will immediately begin using nuclear weapons to solve their problems, but it will seriously erode the norm. One could imagine a world where nuclear weapons are used in combat and nations may decide that they can use nuclear means to accomplish political objectives.
Such a world is not one many people would like to live in. Nuclear war is not a concept that is understood very well because only two nuclear strikes have ever been conducted. We don’t really know how humans will react to the new norm. If the U.S uses a 0.3 kiloton nuclear warhead to decapitate the Kim regime where is the next focal point? Is using a ten kiloton weapon to kill Ayatollah Khomeini acceptable? What about using a 1.5 kt warhead to destroy a North Korean armored division?
In the 72 years After Hiroshima and Nagasaki, humans have through luck, and a careful balance of international diplomacy and implicit bargaining managed to avoid using nuclear weapons in warfare. The use of such weapons has the potential to throw mankind into the abyss. If they are ever used again it could destroy their status and lead to their use in other conflicts.
The focal point must be preserved, if it is not, a new era in human history may emerge, where limited nuclear warfare is an accepted use of force.