A "perfect storm" of falling troop numbers, geopolitical tensions and funding crises is jeopardizing international peacekeeping efforts, a new study has warned.

International peacekeeping missions are in peril due to global geopolitical deadlock, funding issues and declining personnel numbers, the Stockholm International Peace Research Institute (SIPRI) said Monday.

Missions managed by the United Nations have been particularly affected, a SIPRI study said.

The analysis found that just under 79,000 personnel were deployed in international peacekeeping missions at the end of 2025, its lowest point in 25 years and 49% lower than in 2016.

A 'perfect storm'
"If things continue in this way, we could see a dramatic weakening of multilateral conflict management and the near-complete sidelining of institutions like the United Nations," said Jair van der Lijn, SIPRI's director of peace operations and conflict management programme.

"The result is likely to be more conflicts, and these conflicts are likely to have even graver impacts on civilians as states abandon long-established norms," van der Lijn added.

He said the peacekeeping crisis was "due to a perfect storm of funding, political and geopolitical factors."

The UN has had to make "deep cuts to personnel numbers" after large donor countries failed to meet their financial commitments, SIPRI said, resulting in a $2 billion (€1.7 billion) funding shortfall.

Under President Donald Trump, the US has slashed its aid programs and looked to dial back its commitments to international organizations and institutions such as the UN and the World Health Organisation.

The study also said "hardline demands and veto threats from permanent members" of the UN Security Council had "complicated decisions on renewing operation mandates."

As an example, it pointed to the US demanding an end to the UN's Interim Force in Lebanon (UNIFIL) despite repeated violations of a ceasefire between Israel and Lebanon.

Broad support for peacekeeping operations remains
SIPRI warned that the mounting operational challenges facing the UN mean that international crisis responses are increasingly "taking the form of unilateral, bilateral and ad hoc arrangements that are often more militarized and more directly influenced by the self-interest of the states involved."

But despite the challenges, the collapse of the international peacekeeping and conflict management system is not a foregone conclusion, SIPRI Senior Researcher Claudia Pfeifer Cruz said, pointing to broad support for the missions across the UN.

"There is evidently widespread support for UN peace operations in principle," she said. "However, to sustain multilateral conflict management, states will need to go beyond expressions of support — they will need to provide predictable funding and create enough political space to enable effective multilateral responses."