“When something difficult is attempted,” Daniel Berrigan said, “it is like trying to break a rock with an egg.” Berrigan, a Jesuit priest and social radical, who died in 2016, at the age of ninety-four, spent the last third of his life doing something difficult: trying, through protest, civil disobedience, and a steady stream of books and articles, to persuade the nuclear powers to abolish their arsenals. For his efforts, he was frequently called an out-of-touch extremist who changed nothing. But now, when the jousting of Donald Trump and other would-be political strongmen on the world stage are making the nuclear threat appear particularly urgent, there are signs that the Catholic Church has come around to the position that Catholic activists such as Berrigan have resolutely maintained for the past four decades.

Pope Francis has drawn attention to the dangers posed by environmental degradation, income inequality, and the “culture of waste.” He will turn his focus to nuclear weapons later this month, when he visits Hiroshima and Nagasaki—the cities where, in 1945, the United States dropped atomic bombs—killing, by some estimates, a hundred and fifty thousand people and seventy-five thousand people, respectively. Nagasaki has been the historic center of Japan’s Catholic community since the sixteenth century, and on Sunday, November 24th, Francis will give a public address at the ground-zero site of the nuclear attack on the city. Echoing past Popes, he will doubtless denounce nuclear weapons as a threat to humanity, and their ongoing development as a grave misallocation of wealth and resources. Then he’s expected to go further. Twice in 2017, in diplomatic contexts, Francis made remarks that moved the Church away from its support of nuclear deterrence and toward advocating for the abolition of nuclear weapons and condemning their “very possession.” In Nagasaki, according to Cardinal Pietro Parolin, the Vatican’s secretary of state, Francis will place the authority of the papal office, along with his immense personal authority, in support of that objective and call for the “the total elimination of nuclear weapons.”

A few weeks after the Pope delivers his address, seven Catholics affiliated with Plowshares, a nuclear-abolition movement formed in the nineteen-eighties, will be sentenced for breaking federal laws while carrying out a symbolic action devoted to the same objective. The action took place at the Kings Bay Naval Submarine Base, in St. Marys, Georgia, where six Trident submarines, which carry missiles tipped with nuclear warheads, are berthed. On April 4, 2018—the fiftieth anniversary of the assassination of Martin Luther King, Jr., a native of Georgia—the Kings Bay Plowshares Seven, as they are now known, cut a hole in a security fence and entered the base, singing and praying, and recorded the action with body cams. They hung banners and crime-scene tape, spray-painted slogans, pounded a display of a Tomahawk missile with a hammer, and poured human blood on an official seal of the base, depicting a missile crossed with a submarine. One of them left an indictment against the United States; another left a copy of Daniel Ellsberg’s 2017 book “The Doomsday Machine.” A third read Pope Francis’s statement denouncing the possession of nuclear weapons. They were all arrested, jailed, and charged with conspiracy, destruction of government property, depredation of a naval installation, and trespassing. Four were released on bail after two months; the others remained in jail for more than a year.

On October 21st, the seven went before a jury in a U.S. District Court in Brunswick, Georgia. They pled not guilty, maintaining that they had entered the base not to commit a crime but to prevent one: “omnicide”—the destruction of the human race—by nuclear weapons. Three days later, the jury found them guilty on all counts. They will be sentenced early next year.

In many ways, the Kings Bay Plowshares action was unremarkable. The tactics were typical of the movement’s previous actions: all have involved intended damage to property (a symbolic “disarming”); none have involved injury to people. The purpose, too, was the same: to bear witness to the existential peril posed by nuclear weapons. And, like the others, this action had no direct effect other than to get the participants arrested. Yet, as L. A. Kauffman, an activist and a historian of protest movements, told me, the Kings Bay break-in, which was approximately the hundredth Plowshares action since 1980, reflects a remarkable fixity of purpose. Plowshares (alongside the United Nations, the War Resisters League, and religious movements such as Pax Christi and the Fellowship of Reconciliation) has helped keep the nuclear-abolitionist position visible and, in the process, has rendered it tenable, enabling others—including now, perhaps, the Pope—to embrace it.

Plowshares is often described as an offshoot of the Catholic Worker movement, which was founded by Dorothy Day and Peter Maurin in 1933, on May Day, and took shape as a loose aggregation of radical newspapers, houses of hospitality, and self-sustaining farms, then gradually became a base for nonviolence and anti-war efforts; Day herself was arrested and jailed a number of times for acts of civil disobedience, such as, in the nineteen-fifties, refusing to take part in mandatory civil-defense drills, which she considered acts of preparation for war. (She died in 1980, at the age of eighty-three, and the Church is currently considering her for sainthood.)

Plowshares is also seen as a carrying forward of the Catonsville Nine action of May, 1968, in which a group that included Daniel Berrigan and his brother Philip, who was also a Catholic priest, poured gasoline and soap—homemade napalm—on hundreds of draft files at a Selective Service office outside Baltimore, and set them alight, as an act of witness against the war in Vietnam. (After their sentencing, in April, 1970—members were given between two and three and a half years—four of the nine went underground. Daniel, whom the F.B.I. put on its “Ten Most Wanted” list, remained at large until August. Philip and Daniel ended up serving about thirty months and eighteen months, respectively.)

Plowshares is a movement without a leader, a formal structure, or a base of operations. The closest thing it has to a spiritual center is Jonah House, a community that collects and distributes food to people in Baltimore and advocates for nonviolence, resistance to war, and peacebuilding, which was founded in 1973, by Philip Berrigan and Elizabeth McAlister, a nun with whom he had secretly exchanged marital vows in 1970. (The two left their orders and married in a civil ceremony, in 1973. Philip died in 2002.) Plowshares emerged amid the Cold War imperatives of the nineteen eighties—the arms race and the surging popular movement for a “nuclear freeze.” It has remained focussed specifically—obsessively, some would say—on nuclear weapons.

The movement takes its name and its modus operandi from a direct action that was carried out in September, 1980, when eight activists, the Berrigan brothers among them, entered a General Electric plant in King of Prussia, Pennsylvania, and hammered two nose cones for nuclear warheads. Their aim was to carry out a biblical prophecy, from Isaiah, and “beat swords into plowshares.” According to Art Laffin, an activist and Plowshares historian who lives in Dorothy Day House, a Catholic Worker house in Washington, D.C., there were nine more actions during the arms buildup of President Reagan’s first term, and more than twenty in his second. Nearly half the actions since then have been in other countries, including England, Scotland, Germany, Holland, Sweden, Australia, and New Zealand. Twenty-one have been directed against the Trident submarine missile program. All but six have led to prosecutions. In 1984, Helen Woodson and Carl Kabat, a Catholic priest, participated in the Silo Pruning Hooks action, at Whiteman Air Force Base, in Missouri, and were sentenced to eighteen years in prison—the longest sentences passed on Plowshares activists. (Neither served the full sentence.)