By any measure, 2025 was not a good year for world peace.

Worse, it was just the latest of a decade-long decline of peace and upsurge of war.

As author of a book on world peace and how we can achieve it (that’s literally the title), here’s my assessment.

Peace is on the decline around the world by many measures.

The Armed Conflict Location and Event Data index, a UN-funded independent monitor, reports global conflict has doubled in the past five years.

The International Institute for Security Studies reports a 23% increase in armed conflict in 2025 alone. Approximately 240,000 people were killed by violent conflict in 2025, it reports.

And the Institute for Economics and Peace’s Global Peace Index reported that peacefulness around the world has deteriorated for the sixth consecutive year.

Some of the symptoms of that decline, it reports, include:

War happens when we have rising conflict and declining commitment to the things that produce peace.

Three things are driving those trends:

Nationalist populism in the West and elsewhere is a product of these three transformations, which have unsettled comfortable post-Cold War assumptions about the progress of democracy, wealth, and peace.

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