New research from the Uppsala Conflict Data Program (UCDP) shows that 2025 experienced the highest number of interstate wars since World War II,with 65 state‑involved conflicts and more than 244,600 battle‑related deaths. the surge includes a dramatic rise in civilian killings, most notably in Sudan, and signals a worrying erosion of the post‑war international order.

65 state‑involved conflicts recorded in 2025

The UCDP counted 65 conflicts between states in 2025, the most since the end of World II, according to the agency’s latest report. This figure reflects a doubling of interstate wars for the second year running, climbing from two in 2023 to eight in 2025. Researchers highlighted the wars between Russia and Ukraine, Iran and Israel, India and Pakistan, and Israel and Syria as key contributors to the tally.

Ukraine war accounts for 62% of battlefield deaths

Therese Pettersson, senior analyst at UCDP, noted that the conflict in Ukraine alone caused roughly 97,400 deaths, representing 62 percent of all combat fatalities worldwide last year. the study also identified 13 conflicts that met the definition of ‘wars’—each with at least 1,000 battle‑related deaths—underscoring the lethal intensity of the current environment.

400% surge in civilian deaths linked to Sudan’s RSF

One‑sided violence against civilians jumped to about 76,500 deaths in 2025,a 400 percent increase from 2024 and the highest level since the 1994 Rwandan genocide. The spike is largely attributed to the Rapid Support Forces’ 500‑day siege of El Fasher in North Darfur, where UN investigators described systematic attacks that bear the “hallmarks of genocide.”

Who might trigger a broader great‑power clash?

Magnus Öberg, director of UCDP, warned that the rise in interstate conflict reflects a “breakdown of the world order established after WWII,” citing challenges from Russia, China and the United States. Shawn Davies, co‑author of the study, cautioned that while a full‑scale world war remains unlikely, weakened NATO commitments could raise the risk of regional great‑power confrontations with nuclear implications.

Who will fill the gaps in collective security?

Open questions remain about which nations might step in to uphold or replace collective defense mechanisms as NATO’s resolve appears to wane. The report does not identify specific states that could assume a leading security role, leaving analysts to speculate on future alignments.