(OSV News) — Several U.S. and Japanese Catholic bishops seeking nuclear disarmament are expressing both urgency and wariness, as the United Nations hosts a conference on a non-proliferation treaty at a time when the U.N. head himself admits “arms control is dying.”

In an April 27 statement, the archbishops of Santa Fe, New Mexico, and Seattle joined their fellow bishops from Hiroshima and Nagasaki, Japan, in warning that as “nuclear threats are escalating,” the world is “sliding backwards with massive modernization programs to keep nuclear weapons forever.”

Signing the document were Archbishop Paul D. Etienne of Seattle; Archbishop John C. Wester of Santa Fe, New Mexico; Archbishop Peter Michiaki Nakamura of Nagasaki and his predecessor, Archbishop Joseph Mitsuaki Takami; and Bishop Alexis Mitsuru Shirahama of Hiroshima.

The bishops’ message comes at the opening of the Eleventh Review Conference of the Parties to the Treaty on the Non-Proliferation of Nuclear Weapons (NPT), which is taking place April 27-May 22 at U.N. headquarters in New York.

The conferences have been held every five years since the NPT — the core legal instrument for nuclear disarmament — entered into force in 1970.

Extended indefinitely in 1995, the NPT has in recent years “been eroding,” said U.N. Secretary-General António Guterres in April 27 remarks at the conference. He lamented that “for the first time in decades, the number of nuclear warheads is on the rise” and “nuclear testing is back on the table.”

“The drivers of proliferation are accelerating,” said Guterres. “We need to breathe life into the treaty once more.”

United Nations Secretary-General António Guterres speaks to delegates during a meeting on Nuclear Non-Proliferation Treaty at U.N. headquarters in New York City April 27, 2026. (OSV News photo/Eduardo Munoz, Reuters)

Popes provide moral guide on the issue

In their message, the bishops noted they had formed the Partnership for a World without Nuclear Weapons in 2023 as they commemorated the 78th anniversary of the U.S. atomic bombings of Japan.

“Our four dioceses represent the birthplace of nuclear weapons, the most deployed nuclear weapons in the United States, and the only two cities that to date have suffered atomic bombings,” they said.

The bishops said they “follow in the footsteps” of Pope Francis, who on multiple occasions — including his 2019 apostolic visit to Japan — declared the possession of nuclear weapons “immoral.”

They also quoted Pope Leo XIV’s 2026 message for the World Day of Peace, in which the pope observed that “the idea of the deterrent power of military might, especially nuclear deterrence, is based on the irrationality of relations between nations, built not on law, justice and trust, but on fear and domination by force.”

That statement “gets into the heart of the matter,” said the bishops in their message.

The bishops blamed chiefly “the never-ending refusal of the nuclear weapons states to enter into serious negotiations leading to nuclear disarmament” for putting the non-proliferation treaty at risk of collapse.

With ships below it, a mushroom cloud rises during Operation Crossroads nuclear weapons test on Bikini Atoll, Marshall Islands, in this 1946 handout provided by the U.S. Library of Congress. (OSV News photo/U.S. Library of Congress, Handout via Reuters)

Powers aim to ‘keep nuclear weapons forever’

The nuclear powers’ rationale of deterrence “deflects the blame from their own possession of immoral, genocidal weapons.”

“Why is it that Russia and the United States have always rejected the minimal deterrence of just a few hundred nuclear warheads in order to keep thousands of warheads for nuclear warfighting?” they said. “Why is it that all nine nuclear weapons powers are now spending enormous sums on so-called ‘modernization’ programs to keep nuclear weapons forever?”

The U.S., Russia, China, France, the United Kingdom, Pakistan, India, Israel and North Korea are the nine countries known to possess nuclear weapons.

Out of the 12,331 nuclear warheads in the world, Russia currently has an estimated 5,420 warheads and the U.S some 5,042 warheads as of 2026, according to the Federation of American Scientists.

Nuclear weapons powers “have not upheld their end” of the NPT’s “essential bargain” by which they would negotiate nuclear disarmament, while all other nations would pledge to never acquire such weapons, said the bishops.

They pointed out the NPT “has been absolutely indispensable” in limiting proliferation to three nations not part of the treaty (India, Pakistan and Israel) and to North Korea, which withdrew from the NPT in 2003.

A file photo shows an unarmed AGM-86B Air-Launched Cruise Missile is released from a B-52H Stratofortress over the Utah Test and Training Range during a Nuclear Weapons System Evaluation Program sortie, near Salt Lake City. (OSV News photo/Staff Sgt. Roidan Carlson, U.S. Air Force via Reuters)

Concrete action needed on nuclear weapons

However, said the bishops, the previous two NPT review conferences “have utterly failed to outline any concrete steps toward nuclear disarmament.”

“We don’t see how this one will succeed where the others have failed,” they said.

“Clearly the nuclear threats are escalating,” they said. “The brutal practice of might makes right is ascendant, arms control treaties are gone, and we are sliding backwards with massive modernization programs to keep nuclear weapons forever.”

The bishops expressed hope for an upcoming November conference at the U.N. on the Treaty on the Prohibition of Nuclear Weapons, a more comprehensive instrument adopted in 2017 to address additional aspects of nuclear weapons development and acquisition.

“The Vatican was the first nation-state to sign and ratify the TPNW, the bishops said. “We will be there to help witness its further implementation.”

Gina Christian is a multimedia reporter for OSV News. Follow her on X @GinaJesseReina.

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