According to the pope, rearmament that increases geopolitical tension undermines trust between nations and weakens diplomatic efforts meant to prevent conflict. He warned that military expansion can also redirect money away from social priorities such as education and healthcare while enriching powerful interests linked to the arms industry.

His remarks came as Europe experienced one of the fastest increases in defence spending since the end of the Cold War.

The Political Context: NATO Spending Pressure

The criticism also emerged in the middle of a broader geopolitical debate about NATO funding and burden‑sharing within the alliance.

For years, U.S. President Donald Trump has pushed European NATO members to increase their defence budgets, arguing that the United States carries too much of the alliance’s security costs.

Recent NATO discussions have gone even further, with allies agreeing to ambitious new spending goals—potentially reaching about 5% of GDP on defence and defence‑related investments by 2035, a dramatic increase from the long‑standing 2% target.

These proposals have contributed to a rapid rise in European defence budgets. In 2025, European military spending reached roughly $563 billion, a 12.6% increase compared with the previous year.

Against this backdrop, Pope Leo framed the arms buildup as a moral and diplomatic failure. In his view, pouring resources into weapons risks escalating global rivalries rather than addressing the political causes of conflict.

A Warning About AI‑Driven Warfare

Beyond traditional military spending, the pope also raised alarm about the accelerating use of artificial intelligence in weapons systems and military planning.

He warned that large investments in AI‑enabled weaponry could push humanity toward a “spiral of annihilation” if the technology is used to intensify modern warfare without strong ethical oversight.

The concern reflects a broader debate among governments, scientists, and ethicists about autonomous weapons and AI‑assisted targeting systems. Critics fear that such technologies could lower the threshold for conflict, increase the speed of warfare beyond human control, and create new risks of escalation.

The Pope’s Broader Message

Ultimately, Pope Leo’s speech was less about budgets alone and more about priorities. He argued that international security depends on dialogue, diplomacy, and cooperation rather than an expanding arms race.

By warning against both traditional rearmament and emerging AI‑driven warfare, he framed the moment as a choice: continue escalating military competition or reinvest in diplomacy and institutions designed to prevent war.

His message places the Vatican firmly within the long‑standing Catholic tradition of advocating peacebuilding and caution toward new forms of warfare—especially when technological advances risk making conflicts faster, more destructive, and harder to control.

According to the pope, rearmament that increases geopolitical tension undermines trust between nations and weakens diplomatic efforts meant to prevent conflict. He warned that military expansion can also redirect money away from social priorities such as education and healthcare while enriching powerful interests linked to the arms industry.

His remarks came as Europe experienced one of the fastest increases in defence spending since the end of the Cold War.

The Political Context: NATO Spending Pressure

The criticism also emerged in the middle of a broader geopolitical debate about NATO funding and burden‑sharing within the alliance.

For years, U.S. President Donald Trump has pushed European NATO members to increase their defence budgets, arguing that the United States carries too much of the alliance’s security costs.

Recent NATO discussions have gone even further, with allies agreeing to ambitious new spending goals—potentially reaching about 5% of GDP on defence and defence‑related investments by 2035, a dramatic increase from the long‑standing 2% target.

These proposals have contributed to a rapid rise in European defence budgets. In 2025, European military spending reached roughly $563 billion, a 12.6% increase compared with the previous year.

Against this backdrop, Pope Leo framed the arms buildup as a moral and diplomatic failure. In his view, pouring resources into weapons risks escalating global rivalries rather than addressing the political causes of conflict.

A Warning About AI‑Driven Warfare

Beyond traditional military spending, the pope also raised alarm about the accelerating use of artificial intelligence in weapons systems and military planning.

He warned that large investments in AI‑enabled weaponry could push humanity toward a “spiral of annihilation” if the technology is used to intensify modern warfare without strong ethical oversight.

The concern reflects a broader debate among governments, scientists, and ethicists about autonomous weapons and AI‑assisted targeting systems. Critics fear that such technologies could lower the threshold for conflict, increase the speed of warfare beyond human control, and create new risks of escalation.

The Pope’s Broader Message

Ultimately, Pope Leo’s speech was less about budgets alone and more about priorities. He argued that international security depends on dialogue, diplomacy, and cooperation rather than an expanding arms race.

By warning against both traditional rearmament and emerging AI‑driven warfare, he framed the moment as a choice: continue escalating military competition or reinvest in diplomacy and institutions designed to prevent war.

His message places the Vatican firmly within the long‑standing Catholic tradition of advocating peacebuilding and caution toward new forms of warfare—especially when technological advances risk making conflicts faster, more destructive, and harder to control.