For centuries, many European Christians have proudly declared that following Jesus means rejecting violence. But as Russia’s brutal war against Ukraine drags into its fourth year, even lifelong pacifists are beginning to ask whether peace can survive without the means to defend it.

Christianity Today reports on a moral and theological shift taking place among Europe’s faithful.

Alexander Maßmann, a Christian ethicist who used to oppose to military buildup, now admits, “We are simply faced with naked aggression. There must be some sort of deterrence. To keep the peace, we need security guarantees — and rearmament is helpful in that sense.”

Such a statement would have been unthinkable among Germany’s Protestant leaders a decade ago, when Margot Käßmann, then head of the Evangelical Church in Germany, pushed nonviolence and diplomacy. Käßmann recently repeated her call for a cease-fire in Ukraine and an end to weapons deliveries, reminding believers that “God is not a party to war.”

But not everyone agrees. What has changed the thinking? Russian missiles destroying apartments.

Pacifism risks becoming an ally to the violent when it leaves one side disarmed. Maßmann’s reluctant conclusion echoes the logic of the just war theory: peace may require defending the innocent, even if it means killing other human beings.

This isn’t just a European debate. American churches are divided over whether supporting Ukraine’s defense or Israel’s right to exist contradicts the Gospel of peace. It should be noted that it’s one thing to follow Jesus’ command not to resist an evil person and be willing to surrender your own life in defense of your faith, but Jesus did not command his followers to surrender the lives of others for the same purpose.

Micael Grenholm, a Swedish Pentecostal and advocate of “conscientious nonviolence,” disagrees. “Jesus isn’t telling his followers to give up in the face of oppression or military violence,” he argues, “but pointing to another way that is a stronger, more successful force in opposing evil.” Grenholm cites early Christian examples of Tertullian, Origen and Justin Martyr as well as modern studies suggesting nonviolent resistance can sometimes be more effective than war.

But can that work in the modern world? Nonviolent resistance may frustrate a corrupt regime, but it cannot stop tanks or repel missile strikes. As Ukraine’s cities burn and civilians shelter in subways, many European Christians now face what American theologian Reinhold Niebuhr called “the irony of history” that moral purity, when detached from practical responsibility, can lead to greater injustice.

Even Christianity Today’s pacifist sources acknowledge the point. The German Evangelical Alliance’s political commissioner, Johann Matthies, says he personally leans pacifist but adds that failing to strengthen Ukraine’s air defense is “not only politically shortsighted” but also “cynical.” Every Christian, he said, must ask whether they will “carry a sword — either by serving the military or by voting for political platforms that promote rearmament.”

What Europe’s pacifists are discovering is something many in the West forgot after the Cold War: peace is not the natural state of the world. It is held in place by courage, vigilance and, yes, sometimes arms.

The church must still pray for peace, but it must also remember that sometimes, as Ecclesiastes notes, “there is a time for war.”