By Josh Orsi, The Catholic University of America
In spring 1954, France’s colonial empire in Southeast Asia verged on collapse. Fourth Republic forces found themselves overrun by Vietnamese communist rebels, who by mid-March had cornered a significant French army in northwestern Vietnam. The total defeat of the French at Dien Bien Phu led to the partition of Vietnam and its eventual reunification under communist rule. But in 1954, United States President Dwight Eisenhower strongly considered a vigorous intervention on behalf of the French: a bombing raid, codenamed Operation Vulture, aimed to weaken the Vietnamese siege. A draft of the plan prepared by the Joint Chiefs of Staff even included the option of dropping a trio of small nuclear bombs.
Since 9 August 1945, no atomic weapon has been used in war. Their deployment has been largely restricted, in the Western popular imagination and official strategy, to various apocalyptic scenarios. But early on, this was not the case: three years before Dien Bien Phu, General Douglas MacArthur allegedly proposed dropping several dozen atomic bombs during the Korean War. This willingness to treat nuclear weapons as fundamentally similar to conventional weaponry runs counter to the predominant assumptionthat the A-Bomb had “changed the character of war itself.” According to the late Catholic public intellectual Angelo Maria Codevilla, longtime Foreign Service Officer and translator of Machiavelli, “war’s defining characteristic can only be the violent imposition of one people’s will upon another. The conflict of the combatants’ wills, not their weapons, has made the difference in the violence of wars…. Nuclear weapons do not change this in the slightest.” In view, then, of the nature of war and the principles of proportionality and discrimination, this paper will defend the contention that circumstances exist in conventional warfare in which nonstrategic nuclear weapons may be justly employed, which renders the nonstrategic use of nuclear weapons a matter of prudence.
The argument best begins with a clarification: this paper is concerned with the use of nuclear weapons on the battlefield, not as “weapons of mass destruction” properly so-called; viz., attacks on cities and major population centers such as at Hiroshima and Nagasaki. While such attacks (which may also be carried out by conventional weapons, as at Dresden and Tokyo in 1945) fall within the scope of both war and just-war theory, acts of this kind were unequivocally condemned by the Second Vatican Council in the Pastoral Constitution Gaudium et Spes: “Any act of war which aims indiscriminately at the destruction of entire cities, or of extensive areas along with their inhabitants is a crime against God and man himself. It merits unequivocal and unhesitating condemnation.”
The Catechism of the Catholic Church, citing the above passage, adds the following sentence: “A danger of modern warfare is that it provides the opportunity to those who possess modern scientific weapons – especially atomic, biological, or chemical weapons – to commit such crimes.” Therefore, while recognizing the danger inherent in the possession of “modern scientific weapons,” the Catechism notes that said danger stems from a concern that “such crimes” – that is, the indiscriminate destruction of cities, et al – might be committed. This subtlety indicates that those weapons possess legitimate military ends, which is in tension with Pope Francis’ thus far unfulfilled plan to change the Catechism to prohibit even nuclear deterrence. Indeed, the Holy Father’s idea “that the use of nuclear weapons is immoral…. Not only their use, but also possessing them: because an accident or the madness of some government leader, one person’s madness can destroy humanity,” while delivered following a visit to Hiroshima, fails to acknowledge the distinction within the Catechism, since it presupposes that nuclear weapons are morally distinct from conventional arms.
But whence comes this distinction? Why are nuclear arms regarded as uniquely horrible, when the destruction wrought by them was miniscule when compared to that inflicted on Europe and Asia by conventional forces? Two reasons are readily adduced: their immensely destructive nature, and the terrible and lasting effects of radiation poisoning. While radiation poisoning as a weapon is unique to nuclear warfare, it is no more terrible than the cornucopia of mutilations offered by conventional weaponry. The question of nuclear warfare is therefore a question of proportionality, and the dominant understanding of the West, reflected in the private comments of Pope Francis cited above, is that any military use of such weapons is inherently disproportionate and therefore ethically wrong.
This, however, does not follow. The principle of proportionality, as stated by William Mattison, dictates that the “use of violent force is … ‘proportional’ (or proportionate) when the damage caused by one’s use of force is not above and beyond the force needed to restore a just and peaceful state of affairs.” Two considerations on the nature of war are therefore invited: first, “In war, then, let your great object be victory, not long campaigns,” second, the recognition that arms are only a means for the acquisition of human objectives (returning to Codevilla’s remark, quoted earlier: “the conflict of the combatants’ wills, not their weapons, has made the difference in the violence of wars”).
“War is a mere continuation of policy by other means.” The nature of war is the manipulation, by direct or indirect violence, of the political will of an alien group. Peace is usually attained in two ways: a long, costly, attrition of an enemy’s homeland and population, until the political will of the adversary to continue the conflict is substantially degraded, or a swift, decisive military blow which captures or destroys such a significant portion of a foe’s forces that the same result is achieved. Applying the principle of proportionality, it is evident that while in neither case is just-war theory necessarily violated, there is considerably higher risk in the first. This is especially clear when the second aspect of proportionality, discrimination, is introduced, defined by Mattison as “the claim that in order for the use of force to be just, one must discriminate between combatants and noncombatants, and never intentionally kill the latter” (this rules out decisive attacks on civilian targets, such as acts of terror, which would represent a third method of attaining peace in war).
Discrimination, or more descriptively noncombatant immunity, is the teaching of the Catholic Church, and can be seen in the text of Gaudium et Spes quoted above. However, the principle does not absolutely forbid the killing of civilians; while the death of noncombatants is morally wrong, and should not consciously be pursued in war, it is also recognized as usually unavoidable. Evaluated by the doctrine of double-effect, which in its second criterion (in Grabowski’s formulation) prohibits obtaining a good effect by means of bad, and applied to a military context, the death of civilians cannot be incurred by a direct or proximate attack on civilian infrastructure. In the case of Hiroshima, although the city itself headquartered the Japanese army defending Kyushu, and therefore could be considered a credible military objective, the use of the atomic bomb could be criticized under Grabowski’s fourth principle: the “necessity of a proportionate reason for tolerating an evil effect” and the inherent disproportion between military and civilian casualties.
All of this, however, does not directly bear on nonstrategic or tactical nuclear forces, defined in the 2010 Department of Defense Dictionary of Military and Associated Terms as “those nuclear-capable forces located in an operational area with a capability to employ nuclear weapons by land, sea, or air forces against opposing forces, supporting installations, or facilities.” The question of noncombatant collateral only enters indirectly, in the latter two categories, and the term “operational area” implies the proximity of friendly forces, placing a practical limit on the deployment of nuclear weapons: barring a Samsonesque scenario, the forces deployed should not degrade the forces which deploy them.
What exactly would this look like in practice? A 2016 paper published in the journal of the French Fondation pour la Recherche Stratégique outlined contemporary Russian nuclear strategy, which assumes a moral and practical equivalence between the firepower employed in the 1999 NATO intervention in Kosovo and the use of tactical nuclear weapons. In 2000 (the policy has subsequently been modified), Moscow reserved the right to respond to a major conventional attack with a limited nuclear strike, handicapping a potential invasion and achieving victory in a decisive stroke. More recently, this year’s Department of Defense report to Congress, concerning developments with China, acknowledged the possibility that the PRC’s DF-26 “carrier killer” missile, which would surely be deployed in the event the United States attempted to block an ongoing invasion of Taiwan, could be nuclear-armed.
In both cases, the proposal to use atomic weapons is specifically directed toward military forces. Neither foresees the universal nuclear holocaust predicted by so many during the Cold War. Assume the likelier case of the two: China launches a hypersonic nuclear missile at an aircraft carrier in the East China Sea, sailing to the aid of Taiwan. The almost inevitable outcome would be the swift destruction of the entire carrier strike group and all or most of the 8,000 lives in it, and act multiple times the magnitude of 9/11, but unlike 9/11 an act in war, directed solely at a military target.
While many would doubtless decry the scale and brutality of the attack, under which criteria could it be said to be immoral? Striking an aircraft carrier on the open ocean requires no discrimination between combatants and noncombatants and therefore requires no recourse to double-effect. The alternative, per Mattison, is an appeal to proportionality, and surely many would claim that such an act would be far too destructive to justify, even with conventional weapons (which is a possibility, and the destructive potential of conventional weaponry vis-à-vis atomic arms was noted early on in this paper; one final difference between the two will be considered before the conclusion).
But is that the case? The paradigm presented earlier for achieving peace in war holds forth two military solutions: destructive attrition, or decisive victory. The complete loss of a carrier group might very well through its enormity persuade the United States to seek peace with China and persuade the Taiwanese to surrender peacefully, forestalling the enormous collateral damage that would necessarily result from a Chinese invasion of the island. Parallels can be seen between this and the United States nuclear policy in 1945, with the significant moral difference that the potential use of nuclear forces in this case would respect noncombatant immunity.
A further objection may be adduced: can it really be said that such an attack as described above is proportionate? Why not a nonnuclear missile strike to cripple the carrier and thus hamstring the fleet, not destroy it? A loss of such enormity as speculated might anger the United States into prosecuting a longer war and possibly even escalating the conflict, which raises the possibility of violating proportionality and discrimination and also risks violating the “probability of success” criterion, described in the United States bishops’ 1983 pastoral letter The Challenge of Peace as intended “to prevent irrational resort to force or hopeless resistance when the outcome of either will clearly be disproportionate or futile”. The bishops also acknowledge that “the determination includes a recognition that at times defense of key values, even against great odds, may be a ‘proportionate’ witness,” which might legitimate a long war.
This is an objection worth serious practical consideration, but while it offers other military possibilities in the name of prudence, it cannot be said to conclusively rule out the nuclear option as intrinsically immoral. War, as noted above, is an extension of politics, and is therefore essentially practical. As contended in the thesis of this paper, “the nonstrategic use of nuclear weapons [is] a matter of prudence.” The risks of employing nonstrategic nuclear weapons in a situation such as the one described above, while immensely weighty morally, is not qualitatively different per se from the use of conventional weapons. Breaking the unspoken ban on nuclear warfare which has perdured from 9 August 1945 is another consideration entirely, but, however significant, it is only a consideration.
In conclusion, it does not follow from the principles of proportionality and discrimination that the nonstrategic employment of nuclear arms in war constitutes an intrinsically evil act. The battlefield situations in which atomic weapons might be deployed do not necessarily pose substantial risks to the principle of discrimination, and what the possibility of nuclear and nonnuclear escalation must be kept in mind, the principle of proportionality does not automatically prohibit such a decisive blow as described above. None of this is to make a case for the actual employment of nuclear weapons in warfare, although in light of the willingness of the Russian and Chinese militaries to ignore Western concerns, it may be prudent to consider tactical nuclear options to reduce the risk of strategic escalation in the inability to otherwise respond to a limited strike; consider the option of placing short-range nuclear missiles on Taiwan to destroy a potential invasion fleet. In all cases, however, it must be remembered that the purpose of war is the preservation of peace, and that if the judicious employment of the world’s most powerful weapons furthers that end, it ought not be derided but praised.
 Grant, Rebecca. “Dien Bien Phu.” Air Force Magazine, Aug. 2004, pp. 78–84.
2 Lucas, Jim G., and Bob Considine. “Texts of Accounts by Lucas and Considine on Interviews with MacArthur in 1954.” The New York Times, 9 Apr. 1964, p. 16.
 Codevilla, Angelo Maria. “Nuclear Birthday.” Hoover Institution, 8 Aug. 2018, https://www.hoover.org/research/nuclear-birthday.
 Gaudium Et Spes, 7 Dec. 1965, https://www.vatican.va/archive/hist_councils/ii_vatican_council/documents/vat-ii_const_19651207_gaudium-et-spes_en.html.
 Paragraph 2314. Catechism of the Catholic Church, 1994.
 “The Pope: not using or possessing nuclear arms will be added to the Catechism.” Vatican News, 26 Nov. 2019, https://www.vaticannews.va/en/pope/news/2019-11/pope-francis-press-conference-japan-airplane.html.
 Mattison, William. “The Virtue of Justice and Justice in Waging War.” Introducing Moral Theology: True Happiness and the Virtues, Brazos, Grand Rapids, Michigan, 2008.
 Sun-Tzu, and Lionel Giles. “Waging War.” The Art of War, 1910, p. 28.
 Clausewitz, Carl von. “What Is War?” On War, vol. 1, K. Paul, Trench, Trubner, London, 1918.
 Mattison, “The Virtue of Justice and Justice in Waging War”
 Bamford, Tyler. “The Most Fearsome Sight: The Atomic Bombing of Hiroshima.” The National WWII Museum | New Orleans, 6 Aug. 2020, https://www.nationalww2museum.org/war/articles/atomic-bomb-hiroshima.
 Department of Defense Dictionary of Military and Associated Terms, Defense Technical Information Center, Fort Belvoir, Virginia, 2010, p. 241.
 Colby, Elbridge. “Russia’s Evolving Nuclear Doctrine and Its Implications.” Fondation pour la Recherche Stratégique, 12 Jan. 2016, p. 7.
 United States, Office of the Secretary of Defense. Annual Report to Congress: Military and Security Developments Involving the People’s Republic of China, 2021, p. 93.
 “98.” The Challenge of Peace: A Pastoral Letter on War and Peace, United States Catholic Conference, Washington, D.C., 1983.