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Waiting for Armageddon – Theological and Ethical Aspects Of Nuclear Deterrence

From the beginning, nuclear weapons have carried a sense of ultimacy that required religious language to voice their human significance.1 Following the detonation of the first atomic bomb at the Trinity site in July, 1945, Robert Oppenheimer recited the words of Krishna in the Bhagavad-Gita, “Now I am become Death the destroyer of worlds.” Oppenheimer intuited the latent religious dimension of the Manhattan Project: The atom as the first flash of creation and as the explosive instrument of its annihilation.

When General Leslie Groves inquired why Oppenheimer had named the test explosion Trinity, the physicist replied, “I know what thoughts were in my mind. There is a poem of John Donne, written just before his death, which I know and love :

As West and East
In all flat Maps—and I am one—are one,
So death doth touch the Resurrection.”

Oppenheimer continued, “That still does not make a Trinity, but in another, better known devotional poem Donne opens, Batter my heart, three-person’d God.”2

The first citation from Donne’s Hymne to God in my sicknesse, meditates on dying as the way to resurrection. The second poem, Batter my heart, three person’d God, prays for liberation from all that holds the poet back from surrendering to God. Whether Oppenheimer was unconsciously thinking about his own liberation from the coils of his research or voicing guilt over constructing the bomb, we can only conjecture. Nevertheless, he seems to have been alert to the religious implications of the test.

The Theology of Nuclear Deterrence

Theology is the language in which we articulate the religious dimensions of our experience. Theologians, preachers and religious activists use biblical images to ground their positions on deterrence.3 Consider three root images drawn from the Hebrew and Christian scriptures that have been applied to nuclear weapons: Babel (Gen. 11: 1-32), Armageddon (Rev. 16:16), and the Kingdom of God (Matt. 5:9, 44).

Babel is a story of the construction of an “earthly city,” as Augustine later wrote, “to the contempt of God.”4 The political theorist Michael Oakeshott considered Babel an object lesson in collective ambition.5 It evokes the hubris of technological achievement, an apposite metaphor for construction of the atomic bomb. The French Calvinist Jacques Ellul, for another, found in nuclear power a rigid and irreversible system that resists reform.6

By contrast, Catholic Social Teaching sees technology as in need of conscious human control (Pope Francis (2015), Laudato Si’, nos. 52, 114, 184; henceforth LS). “Never has humanity had such power over itself,” Pope Francis wrote, “yet nothing ensures that it will be used wisely” (LS, no. 104). Humanity’s responsibility for nature, including the use of nuclear energy, is a theme of Francis’ encyclical Laudato Si’ (LS, no. 104, and Pope Benedict XVI (2009), Caritas in veritate, nos. 68-77). Pope Francis’ invocation of human responsibility applies the Second Vatican Council’s teaching on the authentic exercise of conscience in history (Vatican Council II, Gaudium et spes, nos. 9 and 16).

Armageddon represents the Last Battle at the end of history in which God’s enemies are utterly destroyed.7 The prospect of apocalyptic destruction fascinates biblical fundamentalists and readers of dystopian fiction. In Dispensationalist theology, the righteous long for the end of history, and Fundamentalists may even regard nuclear war favorably as an act of divine retribution. Armageddon even provides a hermeneutic for anti-nuclear opinion. Both liberal Christians and secular critics invoke the catastrophic destruction associated with Armageddon to focus attention on the disastrous risks involved in deterrence strategy.8

The Kingdom of God images an everlasting reign of justice and peace. It provides the vision for Christian pacifists who refuse to join in war as well as for meliorist Christians who hope to transform human existence by instituting “a world without war” or, better, one in which the risk of war is far less likely. Christian pacifists condemn nuclear weapons and urge trust in God. Among these were the monk and spiritual writer Thomas Merton and the historian and nonviolent activist Gordon Zahn.9 For committed pacifists, God’s Kingdom has already come and our duty is to live according to its demands, nonviolently.10

Others like the US Catholic bishops in their 1983 pastoral letter The Challenge of Peace, though they believe that the Kingdom has begun, also believe the fullness of the Kingdom is still to be. The incompleteness of the Kingdom allows a complex moral posture embracing both nonviolence and Just War. Accordingly, the bishops’ nuanced just-war position allows just enough ambiguity to make nuclear deterrence credible.

Fundamental Religious Attitudes

The deeper human attitudes and dispositions draw on a single experience to inspire a pervasive response to life as a whole. The relation between symbol and religious affections is reciprocal.11 Symbols can inspire religious attitudes. Alternatively, religious attitudes may incline the imagination to certain metaphors or influence how a person interprets them. The symbols may evoke a particular affection, wariness or trust, e.g., and the affection in turn may lead to construing a particular symbol in a certain way, say, determining whether a nuclear Armageddon is welcomed as divine retribution or serves as a motive to abolish nuclear weapons.

Consider this example. While Augustine is the father of Christian just-war thinking, at one point an overwhelming sense of the chanciness of human existence led him to despair of moral choice in wartime, so that he cast himself on the mysterious ways of God:

“… since the whole mortal life of man upon earth is a trial, who can tell whether it may be good or bad in any particular case – in time of peace to reign or to serve, or to be at ease or to die – or in time of war, to command or to fight, or to conquer or to be killed? At the same time, it remains true, that whatever is good is so by the divine blessing, and whatever is bad is so by divine judgment.”12

Augustine appeals to the image of a remote sovereign God, who dispenses blessing and judgment by no standard but his own whim. The strength of Augustine’s anxious bewilderment informs the image of the sovereign God he applies to the experience of war. There is no hint of God’s goodness or providence, as modern interpretations of human finitude provide.13 Events are beyond human control. Driven by this sentiment, Augustine’s will is immobilized and his mind shuts down. He is unable to make the moral judgments required by the Just War. Thus, in addition to the ordinary rational elements I list above (rational argument, circumstances), one must assess the religious affections that inform the application of the religious symbol.

Both the monk Thomas Merton and the activist Jesuit Daniel Berrigan opposed nuclear arms, but they split over how to resist them. Berrigan and the Catholic Left found inventive ways to demonstrate their rejection of the economy of death with public displays of resistance, acting out their anger against the establishment. They were righteous prophets. Merton, by contrast, believed practitioners of nonviolence needed to show greater unease over the anger in themselves and place their trust in God. “The key to nonviolence,” he wrote, “is the willingness of the nonviolent resister to suffer a certain amount of accidental evil in order to bring about a change of mind in the oppressor and awaken him to personal openness and to dialogue.”14 A genuinely nonviolent response, he argued, “does not insistently demand that persons and events conform to their own abstract ideals,” as the Catholic Left did.15

The Ethics of Deterrence

Ethical debates have stirred around the bomb since before Trinity. Leo Szilard circulated a letter to scientists at the Manhattan Project labs warning President Roosevelt of the dangers of an atomic arms race. Later he continued to warn about the dangers of nuclear weaponry, but his protests never came to the attention of Presidents Roosevelt or Truman. Before and after the bombings in Japan Oppenheimer wrangled with General Groves, Lewis Strauss of the Atomic Energy Commission and the House Un-American Activities Committee over his opposition to further development of the bomb, in particular Edward Teller’s quest for “the Super,” the hydrogen bomb.

The ethical debate evolved with the development of technology and government policy.16 From the earliest days, policymakers differed on whether the weapons should be used at all. Bernard Brodie, whose The Absolute Weapon: Atomic Power and World Order laid the foundations of deterrence theory, argued that atomic weapons were useful only as a deterrent to prevent war. The diplomat George Kennan contended that the weapons were “superfluous to our basic military posture.” Both thought the sole purpose of possessing nuclear weapons came to be to avert their use.


The deterrent posture of the superpowers in the Cold War came to be known as Mutually Assured Destruction or “MAD.” That is, deterrence relies on the fear of an aggressor that a nuclear first strike will result in an unacceptable degree of destruction in a retaliatory attack by an adversary. Strategists divided over the size of the arsenal needed for deterrence. Some advocated a numerical edge to provide survivability for the nuclear force and to project a more imposing threat to adversaries. Others urged that arsenals be only large enough to retaliate following a pre-emptive strike. The expansion of nuclear weapons, these strategists believed, had the perverse effect of decreasing national security.

Strategists like Henry Kissinger, Paul Nitze and Herman Kahn held that nuclear war could be continuous with conventional war, with tactical nuclear weapons permitting escalation short of an all-out nuclear war. The morality of tactical nuclear weapons and nuclear war-fighting came to the fore in debates over the deployment of the intermediate range missiles in Europe during the Carter Administration (1977-81). The moral status of deterrence evoked even greater concern as the first Reagan Administration (1981-85) accelerated the arms race with the Soviet Union and prepared its “Star Wars” Anti-Ballistic Missile system. The administration’s talk of fighting and “winning” protracted nuclear war gave a great spur to the anti-nuclear movement in the 80s.

Defending Basic Values

The hardliners believed that tactical nuclear options offered a way out between massive nuclear retaliation and political capitulation. In the Cold War when Liberal Democracy and Communism were engaged in a titanic ideological struggle, theorists assumed defeat would involve an unacceptable loss of a basic value: political liberty. As Michael Walzer, the premier 20th century just-war thinker, wrote, “We accepted the risk of nuclear war in order to avoid the risk, not of ordinary, but of totalitarian, subjugation.”17 The Jesuit theologian John Courtney Murray, building on the teaching of Pope Pius XII, observed:

“There is no indication that the reaffirmation of the traditional principle of defensive warfare, to which Pius XII was driven by the brutal facts of international life, extends only to wars conducted by so-called conventional arms. On the contrary, the Pope extended it explicitly, not only to atomic warfare but even to ABC warfare.”18

In later years, even some moralists strongly opposed to deterrence were hesitant to apply their conclusions firmly, not only because of the deep values at stake but also because of their perception of the implacable hostility of the ­enemy.19

Even the U.S. Catholic bishops (1983), while condemning nuclear war-fighting and expressing skepticism about tactical nuclear war in The Challenge of Peace, the most influential commentary on the issue, allowed that “the defense of key values, even against great odds, may be a proportionate witness” (National Conference of Catholic Bishops, The Challenge of Peace: God’s Promise and Our Response, no. 98; henceforth CP.) In an exception to their fundamental position, they conceded that a limited nuclear war might be waged to defend a people’s “cherished values” (CP, no. 220). Likewise, Michael Walzer, though fundamentally opposed to deterrence, nonetheless opened a narrow margin for limited nuclear war under the category of “Supreme Emergency” for the survival of a political or faith community.20 He found his warrant in the role political or faith communities serve as “the source(s) of our identity and self-understanding.”21

Deterrence and the Just War

For the most part, ethicists treated fundamental values as questions of marginal concern. Most of the debate over deterrence was conducted in terms of the in-bello principles of proportionality and noncombatant immunity. Beginning with the Second Vatican Council (1962-65), the Catholic Church had condemned, “Any act of war aimed indiscriminately at the destruction of entire cities or of extensive areas along with their population” (GS, no. 80). The condemnation grew out of the atomic bombings of Hiroshima and Nagasaki, but also the wide-area bombing campaigns, known as “obliteration bombing,” against Germany including the fire-bombings of Dresden and Hamburg (GS, no. 80).

For some critics, any use of nuclear weapons, including deterrence, was prohibited by virtue of the axiom that “it is forbidden to threaten what it is forbidden to do.”22 Deterrence, they believed, is participation in a threat to commit murder. Much of the debate during the last years of the Cold War, however, focused on issues of discrimination, whether civilian targets could be reasonably distinguished from military ones in a nuclear exchange.

If nuclear warfighting was forbidden, how did the focus on in-bello norms arise? The shift of policy to waging nuclear war stimulated discussion during the first Reagan Administration on how to wage a limited nuclear war short of Mutually Assured Destruction. In response, realist ethicists, like Paul Ramsey, believed that responsible ethicists had to try to apply just-war norms to this extreme condition.

Ramsey’s fundamental concern was with upholding deterrence; but to do so, he made some dubious moves. He argued that the impact of counterforce nuclear attacks could be limited as to have only tolerable collateral impact on the civilian population.23 Of course, Mutually Assured Destruction made no such distinctions, and actual U.S. targeting practices marked military objectives within civilian population centers. Sixty “military targets,” wrote Michael Joseph Smith, “had been identified within the city of Moscow alone. Even targeting relatively deserted land-based missile sites would cause unprecedented civilian casualties.”24

The British philosopher G.E.M. Anscombe charged Ramsey with “double think about double effect,” the principle of just-war morality that allows collateral civilian damage to venture a narrowly directed attack against the enemy’s military.25 Assessing the arguments for limited nuclear war, the U.S. bishops concluded, “The burden of proof remains on those who assert that meaningful limitation is possible” (CP, no. 159).

The bishops themselves set three conditions for a morally legitimate nuclear deterrent:

  1. Nuclear weapons are permitted solely to ­deter;
  2. the norm for establishing the strength of nuclear arsenals is sufficiency to deter, and
  3. deterrence should be a step on the way toward progressive disarmament (CP, no. 188.)

For thirty years the bishops’ conditional acceptance of deterrence remained the best-known articulation of the Catholic teaching.

The Current Discussion

Skepticism about the moral legitimacy of deterrence has grown because of changes in the background conditions for the practice of deterrence.26 As early as 2005, in light of the changed geopolitical conditions after 9/11, five elder American statesmen, former guardians of the U.S. deterrent led by George P. Shultz, renounced deterrence and advocated nuclear abolition.27 Henry Kissinger, the ultra-realist, explained, “It is not possible for the United States to say no one else can proliferate or build-up nuclear arsenals, while we continue to rely entirely on nuclear weapons.”28

During the Cold War deterrence assumed a bi-polar world, but today we live in a multipolar world with nine nuclear-armed states, four of them (Israel, India, Pakistan and North Korea) outside the Nuclear Non-proliferation Treaty. Another, Iran, after U.S. withdrawal from the JCPOA, again is poised to “go nuclear,” with several more countries assumed to be ready to follow. In addition, there are potential threats from nuclear-armed non-state actors like al ­Qaeda and ISIS. In recent years, moreover, according to the Nuclear Threat Initiative, new technologies, “differences in interpretations of what impacts stability and what triggers escalation” have in combination eroded the supposed logic of deterrence between the superpowers.29

In 2013, the Holy See signaled that, in its view, deterrence had become a cover for the failure to disarm.30 Since then, it has evolved an ethics and a diplomacy opposed to the continuation of nuclear deterrence as a feature of global security. In 2013-14, Vatican delegations participated in the Humanitarian Consequences Movement, a Civil Society initiative that reviewed the mounting evidence for the deleterious human and ecological impact of nuclear weapons.31 Furthermore, it became clear over time, none of the conditions laid down by the U. S. bishops in 1983 were being observed.

In 2017, the Holy See participated in the UN conference to draft a treaty banning nuclear weapons. Later that year it was among the first states to sign and ratify the Treaty to Prohibit Nuclear Weapons. Ultimately, during a 2017 Vatican conference celebrating the treaty, Pope Francis delivered a forthright condemnation of deterrence, saying of nuclear weapons, “the threat of their use, as well as their possession, is to be firmly condemned.”32 The papal condemnation of deterrence is a judgment on a system of defense that has lost its moral legitimacy, and which in an increasingly unstable geostrategic environment presents a heightened risk to the future of humanity and of the planet. In Catholic moral theology and Catholic Social Teaching, theology is only one element in a moral judgment. In addition, to theological principles and religious symbols, there is a tradition of moral argument, and an assessment of fact. Especially since Vatican II, these contingent factors have played a more important role under the method known as reading the Signs of the Times.

1 On “ultimacy” as a way to understand the tacit religious dimensions in secular experience, see Gilkey, Langdon (1969): Naming the Whirlwind: The Renewal of God Language. Indianapolis, passim.

2 See “Code Name Trinity” at (accessed 3.4.2020).

3 On the uses of scripture in interpreting contemporary events, see Gustafson, James M. (1975): Can Ethics Be Christian? Chicago, pp. 117-145; and ibid. (1974): Theology and Christian Ethics (Philadelphia), pp. 121-146. For several theological takes on nuclear weapons, see “The Fire Next Time: Faith and the Future of Nuclear Weapons.” Reflections, Yale Divinity School, Spring, 2009.

4 Augustine (1960): The City of God, Book XIV, Chapter 28. Garden City.

5 See Oakeshott, Michael (1989), “The Tower of Babel.” In: Clarke, Stanley G. and Simpson, Evan (eds.): Anti-Theory in Ethics and Moral Conservatism. Albany, N.Y., p. 185 ff.

6 See Ellul, Jacques (1982): “A Theological Reflection on Nuclear Developments: The Limits of Science, Technology and Power.” In: Wallis, Jim (ed.): Waging Peace: A Handbook for the Struggle to Abolish Nuclear Weapons. New York, pp. 114-121. For Ellul’s quasi-deterministic reading of our technological culture, see his Technological Society. New York, 1964. 

7 See Ellul, Jacques (1977): Apocalypse: The Book of Revelation. New York.

8 Daniel Berrigan (2009) The Nightmare of God: The Book of Revelation (Eugene, OR) elaborates the apocalyptic outlook of a leading Catholic pacifist and anti-nuclear activist. For a secular use of apocalyptic thinking, see Schell , Jonathan (2000): The Fate of the Earth. Redwood City, CA.

9 For Merton’s fundamental stance, see “Blessed Are the Meek: The Christian Roots of Nonviolence”. In: Shannon, William A. (ed.) (1995): Thomas Merton: Passion for Peace: Reflections on War and Nonviolence. New York, N.Y., pp. 87-108; and, “Nuclear War and Christian Responsibility,” pp. 39-58. Also, Zahn, Gordon (1983): “Pacifism and the Just War” in Murnion, Philip (ed.): Catholics and Nuclear War: A Commentary on The Challenge of Peace – The U.S. Catholic Bishops’ Pastoral Letter on War and Peace. New York, pp. 119-131.

10 See Roth, John D. (2002): Choosing Against War. Intercourse, PA.

11 I draw the proposition about the strength of religious affections from the anthropologist Clifford Geertz who observed religious symbols may evoke “powerful, pervasive and long-lasting moods and motivations” which confer on them “an aura of factuality [so] that the moods and motivations seem uniquely realistic.” Geertz, Clifford (1973): “Religion as a Cultural System.” In: The Interpretation of Cultures. New York, pp. 93-135.

12 Reply to Faustus, the Manichean, 22.78. In: Holmes, Arthur F. (ed.): War and Christian Conscience. Grand Rapids, p. 68.

13 See Gustafson, James M. (1975), pp. 94-114; also Evans, Donald (1979): Struggle and Fulfillment: The Inner Dynamics of Religion and Morality. Philadelphia, pp. 49-55 and pp. 73-76.

14 Merton, Thomas (1995), pp. 106-107.

15 Merton, Thomas (1995), p. 108.

16 For an overview of deterrence ethics with arguments on various sides, see Smith, Michael Joseph (1987): “Nuclear Deterrence: The Strategic and Ethical Debates.” In: Virginia Quarterly Review, Winter 87. (accessed 14.3.2020). Also Kaplan, Fred (2020): The Bomb: Presidents, Generals and the Secret History of Nuclear War. New York.

17 Walzer, Michael (2000): Arguing About War. New Haven, CT, p. 48.

18 See Murray, John Courtney S.J. (1960): “Remarks on the Moral Problem of War.” In: Nagle, William (ed.): The Morality of Modern Warfare. Baltimore, pp. 69-71.

19 See Finnis, John, Joseph Boyle, Jr. and Germain Grisez (1988): Nuclear Deterrence: Morality and Realism. New York.

20 See Walzer, Michael (2000), p. 49. For “the Supreme Emergency,” see his (1977) Just and Unjust Wars: A Moral Argument with Historical Illustrations. New York, pp. 251-268, and on nuclear deterrence, pp. 269-283.

21 Walzer, Michael (1977), p. 283.

22 See, for example, Kenny, Anthony (1985): The Logic of Deterrence. Chicago.

23 For Paul Ramsey’s positions, see Stout, Jeffrey (1993): “Paul Ramsey and Others on Nuclear Ethics.” In: Journal of Religious Ethics, 19:2 (June), p. 209-238.

24 In Smith, Michael Joseph (1987), note 32 above.

25 Walzer, Michael (1977) cites the Anscombe comment, p. 279.

26 See Morgan, Patrick and Quester, George: “How History and Geopolitical Context Shape Deterrence,” pp. 3-7, and Mazarr, Michael and Goodby, James E.: “Redefining the Role of Deterrence.” In: Shultz, George P. et al. (eds.) (2011): Deterrence: Its Past and Future. Stanford, CA, pp. 9-20.

27 See Shultz, George P. et al. (2009): “A World without Nuclear Weapons,” Appendix 1. In: Drell, Sidney and Goodby, James E. (eds): A World without Nuclear Weapons: End-State Issues. Hoover, pp. 41-46.

28 Cited in Taubman, Phillip (2012): The Partnership: Five Cold Warriors and Their Quest to Ban the Bomb. New York. Kindle ed., Loc. 4753.

29 See the report “Rising Nuclear Dangers: Diverging Views of Strategic Stability” at (accessed 3.4.2020).

30 For the Holy See’s rejection of deterrence, see Mamberti, Dominique (2015): “Address of the Holy See to the High-Level Meeting on Nuclear Disarmament.” New York, 26 September 2013. In: Nebel, Mathias and Reichberg, Gregory M. (eds.): Nuclear Deterrence: An Ethical Perspective. Geneva, pp. 81-82.

31 For a fuller view of Vatican thinking, see “Nuclear Deterrence: Time for Abolition.” In: Nebel, Mathias and Reichberg, Gregory M. (eds.) (2015), pp. 87-97.

32 Address of His Holiness Pope Francis to Participants in the International Symposium “Prospects for a World Free of Nuclear Weapons and for Integral Disarmament,” 10 November 2017.



Drew Christiansen, a Jesuit priest, is Distinguished Professor of Ethics and Global Human Development at Georgetown University and a Senior Fellow at the university’s Berkley Center for Religion, Ethics and World Affairs. Since 2013, he has worked directly with the Holy See on nuclear disarmament and was a member of the delegation at the UN conference that negotiated The Treaty to Prohibit Nuclear Weapons in 2017. He is editor with Carole Sargent of “A World without Nuclear Weapons” (forthcoming) and has been serving as an editor and contributor to various scholarly journals.