Under the theory of nuclear deterrence, military strategists’ goal is to make use of nuclear weapons on the battlefield untenable by either side and to avoid escalation to full-scale nuclear war.

Considering this goal is particularly timely and poignant as Russia’s war on Ukraine continues to rage after six months, China stokes tensions with Taiwan, and North Korea makes aggressive moves.

Conventional nuclear integration is an ill-defined term used by military strategists as the basis for internal theater planning, when they contemplate employing and using nuclear weapons in support of troops on the ground.

Strategists use this concept to plan for use of nuclear weapons in conjunction or support of the operations of traditional forces; conventional nuclear integration aims to return any nuclear engagement—whether an adversary’s use of a nuclear weapon or a U.S. first strike—to a state of deterrence.

One caution: Many imprecisely use the term “tactical nuclear weapons” to describe the types of weapons that may be used on the battlefield in situations involving opposing ground or surface forces. It simply isn’t a helpful way to look at using or planning to use nuclear weapons, however, since the word “tactical” implies limited to traditional military forces arrayed against each other as the lowest echelon of warfare. Additionally, any use of nuclear weapons has strategic implications, the highest echelon of warfare.

Much more important distinctions include how nuclear weapons are employed, toward what aim, and the explosive yield of the warheads.

If the U.S., the other side, or both sides used a nuclear weapon, the goal of the U.S. is to return to the state of nuclear deterrence as quickly as possible. To do this, the U.S. has three basic response options:

—An intentional escalation (as a show of force or as a punitive strike).

—A response in kind (firing back a nuclear weapon of similar yield at a similar target).

—A proportional response (that may or may not involve a nuclear weapon).

Unpacking Response Options

Each of these three response options carries different risks that must be considered in reaching the U.S. goal of returning to a state of nuclear deterrence.

It is worth exploring these options to illustrate the complexities of using one or more nuclear weapons on the battlefield and increase understanding of U.S. options in such a scenario, where the goal is avoiding full-scale nuclear war. In reverse order, then:

1. How can a U.S. response be proportional if it doesn’t include use of a nuclear weapon? Again, how did the adversary employ the weapon, with what aim, and what was the yield of the warhead?

If an adversary’s tactical unit employed a low-yield nuclear weapon against a purely military target, perhaps responding with another nuclear weapon against a similar target wouldn’t be an effective response.

If the goal is to return to deterrence, using conventional weapons in response—to achieve a similar effect on our adversary’s military—may be more effective than responding with a nuclear weapon.

The U.S. also could claim a “high road” response and gain national and international support for perceived restraint in not responding with a nuclear weapon.

2.  With a response in kind, the U.S. would execute a nuclear strike on the nation that attacked us first, using the same yield of weapon against the same type of target.

On the surface, the option of a response in kind seems appealing. But often it is the least desirable option, especially when the U.S. goal is to return to a state of nuclear deterrence.

This option also assumes that the U.S. response can find a similar target and have a similar impact, and that the U.S. can communicate this intent to the adversary.

A nuclear strike as a response in kind could escalate or normalize the use of nuclear weapons on the battlefield. Escalating to a full-scale nuclear war would mean an adversary using nuclear weapons against nonmilitary targets, including U.S. cities and infrastructure.  

This doesn’t mean a response in kind is always a bad option, however. Against an adversary such as North Korea, it could be a better option for a U.S. president than it would be against either China or Russia. North Korea not only has a limited nuclear arsenal, its delivery systems aren’t reliable.

If North Korea used a nuclear weapon on South Korea with limited success, it could be reasonable for the U.S. to respond with a low-yield weapon to demonstrate U.S. willingness to use its own nuclear capability, but not in an escalatory fashion. In this scenario, it seems reasonable that such a response could have a deterrent effect.

3. Responding to an adversary’s use of a nuclear weapon with an intentional escalation may seem to be the most provocative option, but this could be the most appropriate response in some scenarios.

Russia has a stated policy of “escalate to de-escalate.” In a U.S. response to a Russian nuclear strike, a show of force and an element of a punitive strike could be effective to return to the state of deterrence.

This would be especially true if the U.S. response were more than a nuclear strike and included elements of cyberspace and space-based targets to demonstrate that America holds the upper hand in any possible nuclear engagements and could cripple Russian options.

Such a U.S. response could make it clear to Russia that retaining the capability it possesses is a better option than continued escalation that could remove Russia’s parity on the nuclear stage.

It Isn’t Just About Nukes

Although conventional nuclear integration is only one component of nuclear strategy, it is important to understand the concept.

A conventional nuclear integration assessment (that is, looking at the use of a nuclear weapon as part of a wholistic assessment of a broader situation) is much more effective than attempting to classify a nuclear weapon as “tactical,” since “tactical” is an artificial distinction with no real bearing on strategy.

Any attempt to classify a nuclear weapon as “tactical” or “strategic” is a futile exercise that doesn’t lead to increased understanding of the scenario in which the nuclear weapon was used. It also limits the U.S. military’s ability to formulate the proper response to return to the desired state of deterrence.

It also is important to understand that America’s options include more than responding with our nuclear arsenal. Conventional nuclear integration is about blending nuclear options with other elements of military power at the battlefield level and attempting to avoid the use of nuclear weapons on nonmilitary targets.

Thus, any U.S. response to an adversary’s use of a nuclear weapon must account for how best to return to a state of nuclear deterrence.

Communicating the U.S. response is as important as the effectiveness of the response. This is equally true in all three broad categories of options outlined above.

If the U.S. were to conduct a non-nuclear response as a proportional move, it would be important to ensure that the adversary doesn’t see this as U.S. unwillingness to use our nuclear arsenal if needed.

If we were able to respond with purely conventional weapons and achieve a military objective similar to the one that the adversary resorted to nuclear weapons to achieve, this could be a powerful message.

But this approach requires the U.S. to communicate clearly to the adversary, the American public, and other nations the intent behind our response.

What America Has to Get Across

To prevent a response-in-kind approach from escalating, the U.S. must accompany it with two messages.

One message would convey the U.S. desire to return to a state of nuclear deterrence and the other would convey that the U.S. is willing and able to make a more devastating response if pressed to do so.

If the U.S. responds to an adversary’s use of a nuclear weapon with an intentional escalation, we first must successfully demonstrate that the response could cripple the adversary.

But the United States also must communicate a desire to return to a state of nuclear deterrence, or risk that the adversary will calculate that it needs to empty its nuclear arsenal before losing the capability to strike back.

Make no mistake: Use of nuclear weapons on the battlefield is a terrifying proposition. But it is important to understand that the scenario of a limited nuclear exchange doesn’t have to lead to full-scale nuclear war.

Understanding U.S. options and clearly communicating possible responses to a nuclear adversary is crucial to returning to a state of deterrence.

To do this, though, America must retain flexible nuclear options and a military edge in both cyberspace and space-based systems.

The ultimate aim of the U.S. military is to deter adversaries from taking actions that are counter to the interests of the U.S. or key allies.

Once we realize deterrence at all levels is linked, America’s nuclear posture gains significantly in importance as part of our overall military power.

The concept of conventional nuclear integration is just one component. But if the U.S. fails at this stage, it drastically increases the likelihood of nuclear weapons being used on the battlefield—and the risk of all-out nuclear war.   

The Daily Signal publishes a variety of perspectives. Nothing written here is to be construed as representing the views of The Heritage Foundation.

Have an opinion about this article? To sound off, please email letters@DailySignal.com and we’ll consider publishing your edited remarks in our regular “We Hear You” feature. Remember to include the url or headline of the article plus your name and town and/or state.