Every week for the past 23 years Catholics have gathered at Myeongdong Cathedral in Seoul for a Mass of Reconciliation for North and South Korea. Last week’s Mass had a unique atmosphere, for it took place days before the historic summit between the North Korean leader Kim Jong-un and South Korean president Moon Jae-in. The celebrant and preacher last week was Cardinal Andrew Yeom Soo-Jung, Archbishop of Seoul and apostolic administrator of Pyongyang. In the 1920s the North Korean capital was such a hive of religious activity that it was known as “the Jerusalem of the East”. But after the Korean War in 1950-53, the Church was driven out of the North, leaving behind a small and scattered community of Catholics. Some 800 to 3,000 faithful are said to remain in North Korea today, out of a population of 25 million. Cardinal Yeom noted that for months “dark clouds of tension and unrest” had hung over the Korean Peninsula. But the North-South summit was “a very precious opportunity of grace” offered by God through the intercession of the Virgin Mary. It did indeed seem that Providence was at work when Kim Jong-un walked (rather awkwardly, as he weighs around 20 stone) over the demarcation line between North and South, clinging to Moon Jae-in’s hand. It was the first time since the Korean War that a North Korean leader had travelled south. The talks seemed to go well: both sides agreed to work for denuclearisation and to formally end the Korean War by converting the armistice agreement of 1953 into a full peace treaty later this year. Yet the summit did not inspire rejoicing on the streets of Seoul. Why? Because the South Korean public remembers that two previous rounds of talks, in 2000 and 2007, ended with similar promises but failed to secure peace. Sceptics point out that Kim did not explicitly promise to give up his nuclear arsenal. They predict that, at some point, the mercurial 36-year-old will retreat back into his hermit kingdom. Yet South Korea’s Catholics are not naïve for feeling hopeful. Less than a year ago, North Korea claimed to be able to wipe out the US territory of Guam with a missile strike. Now a landmark meeting between Kim and Donald Trump could take place this year, in a neutral location such as Singapore. Moon Jae-in, meanwhile, is expected to visit the North this autumn. At Myeongdong Cathedral last week, Cardinal Yeom acknowledged that Koreans will, in all likelihood, have to wait years before nuclear disarmament begins. “Undoubtedly we do not expect that this will be realised in a day,” he said. “It is necessary to keep the dialogue going with patience.” The Catholic Church in South Korea is not large: it accounts for just five million of the country’s 51 million population. But it is influential. Through its prayers and unrelenting calls for peace, it has helped to create an atmosphere in which peace talks between North and South are possible. That is no small achievement.