Is War in Decline?

Tanisha M. Fazal, Is War in Decline? Annu. Rev. Political Sci. 2025. 28:57–73, https://doi.org/10.1146/annurev-polisci-041923-115351

Abstract: The claim that war is in decline has gained considerable traction among analysts and policy makers. This review surveys the empirical data as well as the theoretical arguments for a decline of war. It concludes that, while great power wars have declined since 1945, war in general is not necessarily in decline. Critiques of the claim that war is in decline range from the statistical to the anthropological. While war is not necessarily in decline, though, it has changed. Specifically, a major driver of the putative decline of war—international norms, laws, and institutions—has done more to change how war is discussed and presented than whether it is prosecuted. Stronger the- ories of change are needed in international relations to understand whether these somewhat superficial changes could deepen in ways that produce a true decline in war.

The penultimate paragraph:

The twinning of institutionalized attempts to regulate and limit warfare with observed changes—although not necessarily an overall decline—in war suggests an alternative pathway for change in the international system. Change does not require technological or material power shifts, but it does not always follow the path intended by social actors such as norm entrepreneurs. Norms, for example, can produce important effects even if they take hold to a limited extent. Insofar as actors feel pressure to comply with norms, they may try to create the appearance of compliance while still committing violations; they may, in other words, try to comply with the letter of the law while violating its spirit. The debate over the decline of war provides multiple examples of this phenomenon. War is still war even if it is not formally declared, it does not entail seizing large swathes of territory, and the civilians who get caught in the crossfire are true non- combatants. But the fact that how wars are fought has changed—even if only in an apparently superficial manner—may itself be a harbinger of other, future shifts. A less teleological and more capacious version of the spiral metaphor sometimes used to describe the institutionalization of norms may be apt here (Risse & Sikkink 1999; Risse et al. 1999, 2013). New norms put pressure on others, but displacement of one norm does not necessarily mean the wholesale establishment of another. New norms may realign incentives, but there are some very deep incentives that cannot be easily overturned. Nonetheless, talking about war as if it is a bad (rather than glorious) thing may, in the longer term, make it so.