Catholic bishops remind political leaders that nuclear weapons are immoral.

our new Pope Leo XIV said, “Nuclear arms offend our shared humanity and also betray the dignity of creation, whose harmony we are called to safeguard.”

Cardinal Blase Cupich of Chicago. “We strongly urge both the world and the Japanese government to take this ‘sign of the times’ deeply to heart, and to take immediate steps toward the signing and ratification of the Treaty on the Prohibition of Nuclear Weapon

Bulletin, By John Wester | December 14, 2025

In August, a group of American Catholic Church leaders—including Cardinal Blase Cupich of Chicago, Cardinal Robert McElroy of Washington, DC, Archbishop Paul Etienne of Seattle, and me, the Archbishop of Santa Fe—traveled to Japan to mark the 80th anniversary of the atomic bombings of Hiroshima and Nagasaki. There, we joined our Japanese counterparts—Bishop Mitsuru Shirahama of Hiroshima, Archbishop Emeritus Mitsuaki Takami of Nagasaki, and Archbishop Michiaki Nakamura of Nagasaki—in commemorating the destruction of their cities. Takami is a hibakusha (atomic bomb survivor); he was in his mother’s womb on August 9, 1945, when his city of Nagasaki was bombed. His maternal aunt and grandmother were both killed in the blast.

Eighty years have passed. But the existential threat posed by nuclear weapons is still with us—and it is growing worse every day. In 2019, Pope Francis elevated the Catholic Church beyond conditional acceptance of so-called deterrence. He declared that the mere possession of nuclear weapons is immoral. Nevertheless, the nuclear powers are now spending enormous sums of money on “modernization” that will keep nuclear weapons virtually forever. Meanwhile, in the United States, taxes are being cut to benefit the rich, and economic inequality and homelessness are exploding. This situation is deeply immoral and counter to the Catholic Church’s teachings on social justice.

Today, the United States has entered a new arms race involving multiple nuclear powers, new cyber weapons, and artificial intelligence. Former Defense Secretary Robert McNamara said the world survived the Cuban Missile Crisis only thanks to luck. This is not a sustainable survival strategy: Luck is not eternal. Even the remote possibility of “nuclear winter” makes nuclear disarmament a profound pro-life issue on an immense scale.

The word “deterrence” has been used by successive US presidents to justify nuclear weapons. But that one word is only a half-truth. The United States has always rejected minimal deterrence and, instead, preferred to include nuclear warfighting capabilities—capabilities that can end civilization overnight. Russia has followed the same course. That is why both sides still have thousands of nuclear weapons instead of only a few hundred, with China now racing to expand its own arsenal. That is why the United States plans to spend nearly $1 trillion “to operate, sustain, and modernize current nuclear forces and purchase new [nuclear weapons] forces” in the next 10 years alone.

This is contrary to the 1970 Nuclear Non-Proliferation Treaty, or NPT, in which the non-nuclear weapon states pledged never to acquire nuclear weapons. In return, the nuclear powers promised to enter into negotiations leading to disarmament—a promise that has never been honored. From that betrayal sprang the 2021 Treaty on the Prohibition of Nuclear Weapons (TPNW), which the Vatican was the first nation-state to sign and ratify. The nuclear-weapon states oppose the TPNW, arguing that it does not effectively advance disarmament and could instead fuel further proliferation. But the treaty does nothing more than ban nuclear weapons, just like previous treaties that enjoyed universal support banned biological and chemical weapons, which are also weapons of mass destruction.

A prime example of this nuclear immorality is right in my own backyard of New Mexico.

A whopping $1 billion is being added to the Los Alamos National Laboratory’s annual $4 billion nuclear weapons budget, largely for the expanded production of plutonium “pit” bomb cores. However, no future pit production is to maintain the existing stockpile. Instead, it is all for new-design nuclear weapons that will fuel the new arms race. The development of new weapon systems could prompt the United States to return to explosive nuclear testing, which would have severe proliferation consequences. Meanwhile, the lab’s science, nonproliferation, and cleanup programs are being cut, and research on renewable energies is being zeroed out.

Jobs are often cited by the New Mexico congressional delegation as justification for expanding nuclear weapons programs in New Mexico. But jobs at Los Alamos and Sandia National Laboratories would be far better directed toward peaceful purposes. Nuclear weapon “modernization” diverts money from helping the poor and feeding the hungry—two far more important moral objectives than feeding warheads and war plans. In FY 2026, the Energy Department plans to spend $10.8 billion in New Mexico alone—the same amount as the state government’s entire operating budget. Of that federal money, 84 percent is for nuclear weapons research and production programs. Still, New Mexico remains the third poorest state in the nation and is ranked dead last in the quality of public education and the lives of our children.

People of all faiths—as well as people of no faith at all—need to know that the American Catholic Church is deeply engaged in nuclear disarmament issues. In a message addressed to Bishop Shirahama of Hiroshima on the 80th anniversary of the atomic bombing, our new Pope Leo XIV said, “Nuclear arms offend our shared humanity and also betray the dignity of creation, whose harmony we are called to safeguard.” The Vatican’s Holy See delegation to the United Nations recently called “on all nuclear-armed States to fulfill their obligations under Article VI of the Treaty on the Non-Proliferation of Nuclear Weapons by engaging in good faith negotiations [and] to ratify the NPT, the Comprehensive Nuclear-Test-Ban Treaty, as well as the Treaty on the Prohibition of Nuclear Weapons.” In that same spirit, two years ago, the dioceses of Santa Fe, Seattle, Hiroshima, and Nagasaki joined together to form the Partnership for a World without Nuclear Weapons to work on nuclear disarmament. We invite other Catholic entities to join us.

On August 5, the two American Cardinals present in Japan delivered stirring words from the Hiroshima World Peace Memorial Cathedral, whose bricks contain ashes from the atomic bomb. “We pray that this award [the 2025 Nobel Peace Prize to the hibakusha organization Nihon Hidankyo] may become a light of hope toward a world without nuclear weapons,” said Cardinal Blase Cupich of Chicago. “We strongly urge both the world and the Japanese government to take this ‘sign of the times’ deeply to heart, and to take immediate steps toward the signing and ratification of the Treaty on the Prohibition of Nuclear Weapons.”

“If our gathering here today is to mean anything, it must mean that in fidelity to all those whose lives were destroyed or savagely damaged on August 6, 80 years ago, we refuse to live in such a world of nuclear proliferation and risk-taking,” said Cardinal Robert McElroy of Washington. “We will resist, we will organize, we will pray, we will not cease, until the world’s nuclear arsenals have been destroyed.”