One year after white smoke rose above the Sistine Chapel, Pope Leo XIV has emerged as something few predicted when cardinals elected the Chicago-born Robert Prevost in just four voting rounds: the world's most prominent institutional critic of Donald Trump's administration. What began as a cautious, measured pontificate has, over recent months, sharpened into an open clash of values between the Vatican and the White House.

Prevost, 70, was elected on 8 May 2024 as a relatively under-the-radar candidate — ranked roughly twentieth on most pre-conclave lists — yet he had been one of Pope Francis's closest allies, elevated to cardinal-bishop and placed at the head of the Dicastery for Bishops, the Vatican office responsible for appointing the Church's episcopal leadership worldwide. His early months were defined by deliberate calm: vatikanologists noted the difficulty of extracting headlines from his careful statements, a sharp contrast with the outspoken Francis. That changed at the start of this year, as the geopolitical landscape deteriorated sharply. After US-backed military operations in Venezuela and Iran, Leo grew increasingly direct. A day after the Iran strikes, he told the faithful in St Peter's Square that stability and peace could not be built on "mutual threats or weapons." After Easter, he called Trump's threats to destroy "an entire civilisation" — a reference to Iran — "unacceptable," and encouraged citizens to contact their representatives to oppose war. Days later, Trump struck back, calling the pope "weak" and "terrible for foreign policy" and declaring, "I'm not a fan of Pope Leo." The pontiff replied calmly that he had no fear of the American government and would continue to preach against war. This week, Trump renewed his criticism, falsely implying the pope supports Iranian nuclear weapons. Leo responded pointedly: "If someone wants to criticise me for announcing the Gospel, let them do so with the truth. The Church has spoken for years against all nuclear weapons."

To ease tensions, US Secretary of State Marco Rubio met Leo and Cardinal Pietro Parolin at the Vatican on Thursday. A Holy See statement said both sides "renewed their common commitment to cultivating good bilateral relations" and discussed countries affected by war and the pursuit of peace, though it gave no further detail. Theology scholar Massimo Faggioli of Villanova University — where Prevost studied mathematics in the 1970s — describes the moment as a turning point: "The tension with Trump has given the papacy a different face, one that was somewhat in the shadows before. This is a second beginning for the pontificate." Faggioli frames the confrontation as more than a personality clash: "It is a collision between two visions of Christianity, two different powers. When American political language uses God to legitimise wars, the Vatican must say something."

Beyond the geopolitical confrontation, Leo's first year reveals a leader who governs by consensus and patience rather than dramatic gesture. He has moved back into the Apostolic Palace — which Francis refused — rediscovered the papal summer residence at Castel Gandolfo, and restored certain traditional liturgical practices, including permitting a Latin Mass at St Peter's Basilica. He has quietly reorganised the Roman Curia, placing trusted allies in key positions. Observers describe him as calm, multilingual, physically fit, and managerially experienced — less flamboyant than Francis, but steadily consolidating authority. His upcoming first encyclical, expected to address artificial intelligence alongside peace and international law, is likely to land as early as 15 May — the 135th anniversary of Leo XIII's landmark social teaching document, Rerum Novarum. Travel to Spain and France follows, and in July he is scheduled to visit Lampedusa, the Italian island synonymous with migrant shipwrecks — a date, 4 July, that appears deliberately chosen to coincide with the 250th anniversary of American independence.