Carl von Clausewitz, the celebrated 19th-century Prussian military strategist, is best known for his concept of "friction," that is, the difference between "war as it actually is, and war on paper." Today, when warfare can include the operational use of nuclear weapons, the cumulative consequences of underestimating "friction" could be exponentially more serious. This conclusion is true by definition and thus, thoroughly incontestable.

It further follows, among various other related concerns, that the president of the United States and his senior military advisers need to pay especially close attention to steadily-accelerating risks of an accidental or inadvertent nuclear war with North Korea. Foreseeably, and for the next several years, the most plausible U.S. targets of any North Korean nuclear aggression would be Hawaii and Alaska.

ADVERTISEMENT

In Washington, the optimal American response should not be a too-simplistic reliance upon active and passive defenses, including selective population evacuations and relocations, but rather on suitably compelling U.S. strategies of deterrence.

How might a catastrophic war between the U.S. and North Korea actually begin? For a useful answer, which must now be systematically sought, it is first necessary to clarify that the unprecedented war risks posed by accident or inadvertence could prove starkly different from the attendant hazards of any "deliberate nuclear war."

More precisely, deliberate nuclear war risks could ensue from any Washington-Pyongyang hostilities that are expressly initiated with nuclear weapons, whether for attaining strategic surprise and advantage, or as the presumed result, expected or unexpected, of enemy irrationality.

There is more. In the deliberate nuclear war scenario, before any U.S.-ordered preemptions, North Korea would need to appear both operationally nuclear and psychologically irrational to U.S. intelligence. Washington, therefore, will need to continuously monitor not only tangible North Korean nuclear assets and capabilities, but also the discernible mental health of Kim Jung Un.

Although some might mock this second imperative as plainly unnecessary or simply impossible, it remains entirely conceivable that the "wacky" dictator in Pyongyang has merely been pretending irrationality.

When the U.S. president turns to consider the coexisting and equally fearful prospects of an accidental or inadvertent nuclear war with North Korea, the primary focus should be directed in more institutional directions, that is, toward the expected stability and reliability of Pyongyang's command and control processes.

Should it subsequently be determined that these core C3I processes display unacceptably-high risks of mechanical/computer failure, prospectively indecipherable pre-delegations of nuclear launch authority, and/or highly unpredictable or unreliable launch-on-warning procedures (sometimes also called "launch-on-confirmed-attack"), a still-rational American president would then need to consider launching a wide-ranging preemptive strike. Such a daunting consideration would be imperative.

Moreover, any resultant American resort to "anticipatory self-defense" could be nuclear or non-nuclear and now be indicated without any specific regard to Kim Jung Un's presumed rationality. In other words, now, the operational reasonableness of such a defensive first strike by the United States would not necessarily require any prior judgments of enemy irrationality. At the same time, this calculated reasonableness might still be enlarged or enhanced by such prior assessments.

What would be the most plausible scenario concerning a Trump-ordered preemption against North Korea? When all significant factors are taken into account, Pyongyang, likely having no meaningful option to launching at least some massive forms of armed response, would intentionally target certain designated American military forces in the region, and/or high-value South Korean armaments and personnel.

President Trump Donald John TrumpBubba Wallace to be driver of Michael Jordan, Denny Hamlin NASCAR team Graham: GOP will confirm Trump's Supreme Court nominee before the election Southwest Airlines, unions call for six-month extension of government aid MORE, still assuming enemy rationality, should then expect that whatever its precise configuration of selected targets, North Korea's retaliatory blow would be designed to avoid any massive (possibly even nuclear) American counter-retaliations.

All such incomparably high-consequence calculations must assume perfect rationality on all sides. If, for example, the American president should somehow decide to strike first, the response from Kim Jung Un should then expectedly be proportionate, that is, more-or-less similarly massive. In this particular escalatory scenario, the willful introduction of nuclear weapons into any ensuing conflagration might not simply be dismissed out of hand by either state party.

At that markedly-uncertain point, such a "game-changing" introduction would more likely originate from the American side. This critical inference is based upon the understanding that while North Korea already has some nuclear weapons and missile delivery vehicles, it is also still rational and still not operationally-prepared to seek "escalation dominance" vis-à-vis the United States. In other words, for now at least, it would seemingly be irrational for Pyongyang to launch nuclear weapons first.

Sometime, in principle, at least, President Trump, extending his normally favored stance of an argumentum ad bacculum, could quite rationally decide upon a so-called "mad dog" strategy. Here, choosing a plan that has nothing to do with the nickname of his own secretary of defense, the American president, following his just-ordered preemption, would deliberately choose a strategy of pretended irrationality.

Any such determined reliance, while intuitively sensible and arguably compelling, could backfire, thereby opening up a fearful path to now unstoppable escalation. Such a self-propelling competition in risk-taking could also be triggered by the North Korean president, now pretending to be a "mad dog" himself. A feigned irrationality stance of Kim Jung Un might be undertaken exclusively by the North Korean side, or in an entirely unplanned tandem, "together" with the United States.

It is also conceivable, in such unprecedented escalatory circumstances, that the North Korean president would no longer simply be pretending irrationality, but would in fact have become genuinely irrational.

If President Trump's initial defensive first strike against North Korea were conspicuously less than massive, a still-rational adversary in Pyongyang would likely take steps to ensure that his own chosen reprisal was correspondingly limited.

But if Trump's consciously-rational and calibrated attack upon North Korea were wittingly or unwittingly launched against an irrational enemy leadership, the response from Pyongyang could then be an all out retaliation. This presumptively unanticipated response, whether non-nuclear or some non-nuclear-nuclear "hybrid," would be directed at some as yet undeterminable combination of U.S. and allied targets.

By any measure, this response could inflict exceptionally far-reaching harms.

Looking ahead, it is now credible that a North Korean missile reprisal against U.S. interests and personnel would not automatically exclude the American homeland. However, should the North Korean president maintain determinedly rational judgments, he would almost certainly resist targeting any calculably vulnerable portions of the American homeland in Alaska or Hawaii. Of course, should he still be willing to strike targets in South Korea and/or Japan, he would plainly still incur the substantial risk of a U.S. "collective defense" nuclear counter-retaliation.

Such a risk would be much greater if Kim's own aggression extended beyond hard military assets, either intentionally, or as the unwitting "collateral damage" brought to "soft" civilian populations and to certain corollary infrastructures.

Even if the stunningly complex "game" of nuclear brinksmanship in Northeast Asia were being played only by fully-rational adversaries, the rapidly bewildering momentum of events between Washington and Pyongyang would still insistently demand that each contestant strive relentlessly for escalation dominance.

Ominously, it is in the entirely unpracticed dynamics of such an explosive rivalry that the palpable prospect of an authentically "Armageddon" scenario could be actualized. This unambiguously intolerable outcome could be produced either in unexpected increments of escalation by either or both of the dominant national players, or instead, by any sudden quantum leap in applied destructiveness undertaken by the United States and/or North Korea.

For Carl von Clausewitz, "friction" describes the always-vital difference between theory and reality in military calculations. The only element that is now wholly predictable in deciphering such hideously complicated U.S.-North Korean calculations is the situation's utterly boundless unpredictability.

Accordingly, even under the very best or optimum assumptions of enemy rationality, all relevant decisionmakers would have to concern themselves with potentially dense or confused communications, inevitable miscalculations, cascading errors in information, unauthorized uses of strategic weapons, mechanical or computer malfunctions and poorly-recognized applications of cyberdefense and cyberwar.

To be sure, nuclear strategy is a "game" that President Donald Trump could soon have to "play" with North Korea — and total game avoidance might well be the least desirable posture for the United States. But he should nonetheless prepare to proceed with maximum insight and abundant caution.

Louis Rene Beres is professor emeritus of political science at Purdue University. Beres' lectures and research focus on international relations, terrorism and international law. He is the author of several books, including, "Surviving Amid Chaos: Israel's Nuclear Strategy," which was published in 2016 by Rowman & Littlefield.

The views expressed by contributors are their own and not the views of The Hill.