Pope Leo XIV on Wednesday warned of the growing risk of a “new arms race” as the last remaining nuclear arms control treaty between the United States and Russia is set to expire, raising concerns over global security and stability.
The New START treaty, the final nuclear agreement still in force between Washington and Moscow after decades of Cold War–era arms control deals, is due to expire on Thursday. With its expiration, restrictions on the world’s two largest nuclear powers would lapse.
Addressing his weekly general audience, Pope Leo urged global leaders not to abandon the treaty without ensuring a meaningful and effective follow-up. “The current situation requires us to do everything possible to avert a new arms race, which further threatens peace between nations,” he said.
The pontiff, the first American to lead the Catholic Church, stressed that the world must move away from fear and mistrust. He called for “a shared ethic capable of guiding choices towards the common good,” saying this approach is more urgent than ever in today’s tense geopolitical climate.
Russia has offered a one-year extension of New START, and US President Donald Trump had previously said such an extension “sounds like a good idea.” However, no concrete progress has been made. The treaty was originally signed in 2010 by then-US President Barack Obama and Russian President Dmitry Medvedev and includes verification and monitoring mechanisms.
Relations between the two countries have deteriorated in recent years, particularly over the war in Ukraine. Russia suspended on-site inspections during the Covid-19 pandemic, while both sides have accused each other of obstructing monitoring activities. In 2023, Moscow formally froze its participation in the treaty, though it has continued to voluntarily observe its limits.
Tensions have further escalated with Russia testing new nuclear weapon delivery systems without warheads and Trump announcing the movement of two US nuclear submarines closer to Russia, underscoring fears of a renewed nuclear standoff.
