The Macroeconomics of Defense Spending, Conflicts, and Recovery

Why It Matters

Understanding the macroeconomic fallout of wars and defense booms helps policymakers and investors navigate fiscal trade‑offs, inflation risks, and growth prospects in a world where geopolitical tensions are resurging.

Key Takeaways

• War reduces output 3% initially, 7% after five years.
• Defense spending spikes raise short‑term growth but increase debt.
• Post‑conflict economies often relapse; 40% resume fighting within five years.
• Large defense booms are mainly financed by deficits, cutting social programs.
• Joint European borrowing could boost defense capacity while sharing fiscal burden.

Summary

The International Monetary Fund’s new research, slated for the World Economic Outlook next week, examines how wars and surges in defense spending reshape macroeconomic fundamentals. Drawing on data from 164 countries since 1946, the study quantifies the economic toll of conflict and the fiscal dynamics of defense booms, offering a timely lens as the Iran war and other tensions flare. Key findings show that wars shave roughly 3% off output at onset, deepening to a 7% loss within five years and persisting for a decade, outpacing losses from financial crises or natural disasters. Defense‑spending episodes—defined as a rise of at least one percentage‑point of GDP for two‑year spans—have become more frequent, averaging a 2.7‑point GDP increase financed largely by deficits, which push debt up by about seven points and crowd out health, education, and social protection. The authors highlight stark statistics: over 35 nations faced internal conflict in 2024, affecting 45% of the global population; since 2010, 1.9 million deaths and millions of refugees have resulted. In post‑war settings, roughly 40% of countries relapse into conflict within five years, and recovery is hampered by weak labor and capital growth. European policymakers are urged to consider joint borrowing and domestic procurement to mitigate import leakages and enhance technological spillovers. For governments and investors, the research underscores a delicate balance: while defense spending can deliver a short‑run demand boost, it carries inflationary pressure, deteriorating fiscal and external balances, and long‑term opportunity costs. Coordinated financing and smarter procurement could preserve security without sacrificing essential social investment, shaping fiscal strategies in an increasingly conflict‑prone world.

Original Description

IMF economists Andresa Lagerborg and Hippolyte Balima join Moritz Schularick president of the Kiel Institute for the World Economy, to discuss the macroeconomic effects and policy tradeoffs associated with higher defense spending, as well as the macroeconomics of conflicts and recovery.

https://www.imf.org/en/publications/weo/issues/2026/04/14/world-economic-outlook-april-2026?cid=sm-com-yt-sm26-WEOEA2026001