Christians need to reexamine the issue of nuclear weapons. Most of us probably haven’t thought about it recently. With everything else going on, it’s not top of mind. But now is the time to reconsider seriously the moral challenge of nuclear weapons in the modern world.

Pope Benedict raised the issue in 2006. Pope Francis raised it again in 2017 with a condemnation of the threat of nuclear deterrence. Many Christians—including previous popes—have said that in the moral calculations of war, threatening to use these weapons in order to stop other people from using them was justified. Now the Roman Catholic Church disagrees, and Pope Francis says a threat “is to be firmly condemned.”

There is also renewed debate over a comprehensive ban on all nuclear weapons. Eighty-one countries have signed on to the Treaty on the Prohibition of Nuclear Weapons, sometimes called the Ban Treaty. A debate about it was set to take place in New York City this month, but it has been delayed one year due to concerns about COVID-19.

At the same time, the New START Treaty between the US and Russia is set to expire. This treaty—the descendant of the agreement first proposed by President Ronald Reagan and signed by President George H. W. Bush—has continued important historic efforts to put real restraints on nuclear weapons. If it sunsets in February 2021, there will be no constraints at all on nuclear weapons for the first time in half a century. President Donald Trump and President Vladimir Putin can extend the treaty for five years, but so far it’s not clear that they will, although the ball appears to be in Trump’s court.

These three things should compel Christians to take up the moral challenge of nuclear weapons. It’s time for Christians, particularly in America, to think deeply about our stance on the issue.

How Christians have thought about nukes

Protestants have never had one view on nuclear weapons. Perhaps the most incisive moral thinkers from the mainline churches were Paul Tillich and Reinhold Niebuhr. Their observation of war and the Holocaust, combined with their beliefs about the reality of sin and evil, led them to argue that nuclear weapons were necessary. Nuclear deterrence was acceptable, they said, at least in the current global conditions. Their view was never unanimous, though.

Evangelicals have been espcially divided. They are “the great undecided group,” according to a National Association of Evangelicals (NAE) report in 1983.

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The NAE, however, has advocated for nuclear nonproliferation treaties, and Christianity Today has long argued for a “carefully phased negotiation process—ultimately to encompass all nations, and aiming first at the reduction and then at the repudiation of all weapons.”

The Catholic Church, in contrast, can speak with an official voice and has a great body of thought on the moral questions of war. Back in the fifth century, Augustine of Hippo formulated the theory of “Just War,” which was further developed by Thomas Aquinas in the 13th century. The official teaching says a war is just if it is under the auspices of a proper authority and has a just purpose. Peace must be a central motive, even during violence. The theology allows for the prohibitions of particular weapons. There was a papal proclamation against crossbows in medieval times, for example.

Most Catholic thinkers have not opposed nuclear weapons in and of themselves, though. In 1982, Pope John Paul II said that nuclear deterrence is “morally acceptable,” provided it is a provisional measure “on the way to progressive disarmament.” The current pope has said the conditions that would make nuclear weapons morally acceptable are no longer being met. Pope Francis condemned nuclear weapons unilaterally, saying “the threat of their use, as well as their very possession, is to be firmly condemned.” He reiterated this statement in a visit to Hiroshima and Nagasaki in 2019.

This creates a dilemma for devout Catholics in the armed forces or who are associated with national defense in the private sector. Can they continue in good conscience?

Protestants appear to have paid little attention to this dramatic change in Catholic thinking, but we would do well to think about this moral challenge to nuclear weapons.

New push for a new treaty

The second challenge to rethink nuclear weapons and nuclear deterrence comes from the new treaty proposing a comprehensive prohibition on all nuclear weapons and their delivery systems. A group of 122 countries put forward the Treaty on the Prohibition of Nuclear Weapons at the United Nations in 2017. It now has about 81 signatures and 36 ratifications and would go into effect, for parties to the treaty, when it has been ratified by 50 countries. Of course, it would place no legal obligations on nations that have not signed on to the treaty.

Treaty advocates have generally not used religious or overtly moral arguments in its justification. Rather, they have appealed to “Humanitarian Law” and the Geneva Conventions of 1949 and 1977. The conventions say that military responses must be proportional and should make every effort to distinguish between combatants and non-combatants. Both are difficult to impossible with nuclear weapons.

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The treaty’s advocates have also pointed out that under some scenarios, nuclear war could produce a “nuclear winter,” resulting in a decrease in temperatures that could have a devastating effect on world agriculture.

There are some strong objections to the ban treaty, though. It lacks definitions, elimination procedures, and any regimen for verification. It is also strongly opposed by states that actually possess nuclear weapons, so it is difficult to see how it will have any real impact.

The New START Treaty, on the other hand, has placed constraints on nuclear weapons and continues the work of its predecessor agreements that resulted in significant reductions. There are still about 15,000 nuclear weapons in the world, though, which is a lot. An extension of this treaty is top priority for the arms control community and has been backed by some Christian groups, including the NAE.

Starting proposals for Christians to support

These discussions ought to push us to think about the morality of nuclear weapons and defense policy. Sincere Christians will differ on how to deal with all these high-stakes dilemmas. Perhaps agreement could be found on certain modest near-term policies and actions.

I want to propose five points of agreement as a starting place. Christians should:

  • Support the extension of the New START Treaty while seeking more ambitious measures to succeed it.
  • Press for substantial reductions in the numbers of nuclear weapons—especially in the US and Russia.
  • Ask presidential and congressional candidates where they stand on nuclear weapons and have them explain what realistic plans they have for dealing with proliferation.
  • Support nonproliferation efforts to prevent the further spread of nuclear weapons to additional countries or non-state actors.
  • Support efforts to resolve serious regional issues that involve nuclear weapons—in particular, issues in the Middle East, South Asia, and the Korean Peninsula.

There will be no sudden leap to a world free of nuclear weapons. Nor does the current status quo seem sustainable. It’s up to us, then, to do something. With the moral challenge of the pope’s statements, the push for the ban treaty, and the deadline for extending New START, Christians should take this moment to engage the problem of nuclear weapons, to think seriously about what can be done.

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Edward Ifft is a distinguished visiting fellow at the Hoover Institution, Stanford University. A retired State Department official, he has more than 40 years of experience negotiating and implementing nuclear arms control agreements.

"Speaking Out" is Christianity Today's guest opinion column and (unlike an editorial) does not necessarily represent the opinion of the publication.