The risk of nuclear war, whether by accident or deliberate launch, is higher now than it has been since the Cuban Missile Crisis. President Kennedy then estimated we faced a one in three chance of nuclear war. But the current dangers may provide opportunities for peacebuilding. Catholic just peace principles and practices can help deescalate nuclear weapons dangers. They have been tested by fire in war zones around the world, and provide ethical and practical guidance as well as a practical theory of change.
It is unrealistic and dangerous to claim that the future of nuclear weapons will look like the past. It is particularly reckless to make such assumptions in a period of rapid global change, including unanticipated shocks like the war in Ukraine. The drone and AI wars in Ukraine expose the vulnerabilities of legacy weapons systems to new, cheaper, and widely available technologies. But these vulnerabilities, as well as the shocks of President Putin’s nuclear saber-rattling, can provide the impetus for building a sustainable, just peace.
Just peace is not idealistic; it is history. Bad times provide moments for unlikely breakthroughs. Thirty years ago, an era of historic U.S.–Russian peacebuilding was made possible by the unexpected shocks of a stalemated Soviet military campaign in Afghanistan, and then by a failed coup attempt in 1991. These events led to joint projects that improved nuclear security and safety, as well as to the unprecedented agreements to reduce nuclear weapons, which we are still benefiting from today. The groundwork for these successes was built earlier. The Church, for example, repeatedly called for the elimination of nuclear weapons and supported the Solidarity movement in Poland, which helped end the Cold War. Research interviews I’ve conducted with U.S. policy makers, like then-senator Sam Nunn and General William F. Burns, revealed that they started the relationship-building and efforts at nuclear risk reduction before the shocks that brought an end to the USSR. They didn’t wait for better times to act.
The Church and others are preparing to once again open space for such breakthroughs, identifying projects of common interest and promoting dialogue, encounter, and integral human development.
Catholic practices and principles of just peace can move us back from the nuclear brink. The Catholic Church’s stance on nuclear weapons has evolved in parallel with Catholic teaching on just peace; with the Church’s experience in peacebuilding in conflict zones throughout the world, including Latin America; with the Church’s demographics; and with the Global South’s perspective on nuclear weapons. Catholic teaching on war and peace is sometimes presented as bifurcated, pitting the just war tradition against just peace. But Catholic teaching, including the just war tradition, has always been predicated on the pursuit of a positive, just peace based on right relationship. This is why the Church, before nuclear weapons were ever built, urged that they never be created. The Church repeatedly
criticized nuclear weapons and nuclear deterrence throughout the Cold War as being “certainly not” a stable, moral, long-term basis of a positive peace, and called for their elimination, disarmament, and for the use of negotiation, international law, and multilateral institutions to get rid of nuclear weapons.
Just war tradition (JWT) is necessary but not sufficient to navigate the moral and practical challenges posed by nuclear weapons. As I wrote in The Berkeley Forum:
JWT tells us how to limit war, but it tells us nothing about how to build peace. Nuclear weapons violate JWT. They do not discriminate between combatants and noncombatants, and they are not proportionate. But while JWT tells us why nuclear weapons are impermissible, it offers no ethical or practical guidance for removing them in nuclear disarmament. In contrast, just peace principles and practices have worked in war zones around the world, helping to disarm and transform relationships of conflict into more sustainable, equitable relationships.... [W]e must now apply just peace principles and practices to nuclear disarmament.
The Church’s work on the Treaty to Prohibit Nuclear Weapons (TPNW) is an example of this work. It is not, as some have argued, an unrealistic “prophetic indictment” that risks making the Church irrelevant. Such critiques reflect a lack of an empirical and theological understanding of how just peace works. Peace does not drop down from heaven; it is built through long-term engagement that often produces breakthroughs when conditions seem most adverse. Catholics have gained hard-won experience in building positive, more just peace, from the work to end destructive wars in Colombia, Ireland, and Mozambique; to the Solidarity movement in Poland; to the People’s Power movement that brought democracy to the Philippines.
This on-the-ground experience has translated into theological, philosophical, and legal frameworks for the principles and practices of just peace. All the formulations of just peace—including my own but also those of Daniel Philpott and others—share a holistic approach to peacebuilding that prioritizes human life and dignity and fosters positive social relationships at all levels. Peacebuilding is not just the work of government elites.
These efforts reflect and respond to changes in the Church itself. Vatican II was not only a reboot of religious rites and rituals and an update of organizational structures. It was also a decolonization of Catholicism, in theology, outlook, organization, and practice. The Church’s work toward disarmament counters nuclear colonialism, which has seen nuclear weapons detonated over two thousand times, harming Indigenous communities, women, and children. Two-thirds of the world’s Catholics now live in the Global South, and ideas and practices from its communities are taking root in Catholic ethics and practice. Pope Francis is the first pope from the Global South, but he will not be the last. Francis’s papacy has sought to make the Church more synodal and conciliar, encountering and dialoguing with voices at the “ends of the earth.”
Pope Francis and Holy See diplomats have repeatedly noted that no state has “legacy rights” to possess nuclear weapons forever. The assumption of the morality of nuclear deterrence held by nuclear-weapons-possessing states can no longer be thought to prevail over the views of the Global South. Its nations have called for deep reductions in nuclear arms and action to heal the harm caused by the manufacturing, testing, and possession of nuclear weapons. Latin America created the world’s first Nuclear Weapons Free Zone, and helped develop the Non-Proliferation Treaty, which led to the rolling back of nuclear weapons programs in nearly two dozen countries.
Catholic teaching is shifting to focus on a just peace tradition. In my research from war zones around the world, I posit the following just peace principles and practices: widening participation, restoration, relationship building, reconciliation, and sustainability.
In peacebuilding, we say that if you do not have a seat at the table, you may find yourself on the menu. Previously, nuclear weapons policies and treaties were made without the participation or consideration of the victims, including women, children, and Indigenous people. But the moral and legal norms governing nuclear weapons have already changed dramatically in recent years, in part due to the application of just peace principles. The TPNW, which I helped negotiate on behalf of the Holy See Mission to the United Nations, included victims who testified to the human and environmental harms of nuclear weapons. Including these voices changed the outcome of the negotiations, just as it has changed the trajectory of peace negotiations in countries like Colombia. Ongoing TPNW negotiations allow themselves to be moved by this participation—by encuentro, or dialogue.
The TPNW entered into force in 2021, closing a legal loophole in international law. All other weapons of mass destruction were previously banned, as they violated international humanitarian law and the laws of war. Now nuclear weapons are banned as well, expanding prior regional treaties that had banned nuclear weapons in most countries. The ban is the latest expansion of humanitarian arms control, prohibiting the use, possession, production, stockpiling, sale, and transfer of nuclear weapons, and requiring environmental remediation and assistance to victims of nuclear weapons testing, use, and production. Even countries that do not enter into the treaty find themselves impacted.
Secondly, restoration addresses the needs of those harmed by violence. TPNW negotiations are now underway to establish an international fund to cover the costs of people harmed by nuclear weapons use and possession. Past examples of nuclear restoration include the joint Megatons to Megawatts Program of the United States and Russia, in which the fissile material from decommissioned nuclear bombs was turned into electricity. At the height of the program, ten percent of the electricity in the United States came from decommissioned nuclear bombs. President Trump’s executive order declaring an energy emergency may provide an opening to resume those efforts.
Right relationship—creating or restoring just social connections—can be fostered in practices of acknowledgment, respect, and efforts to correct unjust patterns of exclusion and exploitation. In the context of disarmament, right relationships of trust can be built through regular interactions like inspections, transparency, and accountability. Negotiations around a new agreement between the United States and Russia to follow the New START Treaty, which expires in 2026, may provide the opportunity to build such robust relationships.
The fourth principle, reconciliation, includes truth-telling and public acknowledgment. There has been little transparency surrounding nuclear weapons. The TPNW created the Scientific Advisory Group and other processes to increase transparency and accountability around the humanitarian and environmental impacts of nuclear weapons. Ireland and New Zealand championed the creation of a similar UN scientific panel to report on the physical effects and societal consequences of a nuclear war. Disseminating this information to wider audiences will make it harder for nuclear-armed states to continue to avoid truth-telling about nuclear weapons.
Finally, just peace must be sustainable and take root over time and space. Some of the most poisoned places on planet Earth are nuclear weapons sites, including the abandoned uranium mines on Native American lands in the U.S. Southwest, and nuclear weapons production and storage sites. The TPNW shares lessons learned and best practices in cleaning up the environmental legacy of nuclear weapons. This provides an opportunity for collaboration with nuclear-armed states, many of which have limited laws in place obligating them to address environmental damage.
Some oppose applying just peace principles to nuclear weapons. Conventional wisdom holds that “nuclear weapons are different,” that principles and practices developed to transform conventional conflicts do not apply to nuclear weapons. According to adherents of this status-quo ideology, because of rising nuclear risks, the preconditions for deeper nuclear disarmament are not met. Attempts at peacebuilding, they hold, are unrealistic at best and dangerous at worst.
But it is nuclear deterrence policy that is deeply unrealistic, while just peace approaches are practical, achievable, and moral. From the peacebuilding perspective, none of these adverse conditions are disqualifying; they are precisely when peacebuilding is pursued by a range of nonstate and state actors. Hurting stalemates may create incentives to pursue alternatives. Because peacebuilding is not restricted to state activity, it continues even when government elites are stalemated or are escalating conflict. Peacebuilding also extends over very long timelines and includes wider varieties of actors pursuing peace through multiple channels, not knowing where the breakthrough may come. From this perspective, nuclear weapons are a symptom of frozen conflict and the inadequate use of standard peacebuilding practices. Giving up entrenched arsenals is a normal part of peacebuilding. Nuclear weapons are an outdated, dangerous technology. Militaries routinely give these up, from chariots to the horse cavalry. Championing just peace, the Catholic Church encourages multiple avenues back from the brink.
This article was published as part of a symposium titled “The Path Toward Disarmament.” The other contributions to the symposium can be found here:
Archbishop John Wester, “A First Step”
Raymond J. Juzaitis, “The Need for Deterrence”
J. Bryan Hehir, “A Pluralistic Ethic”
