Differences in birth rates between countries can affect their demographics, with dire implications for national security. These differences can shift states’ relative economic and military power. They can also alter comparative standards of living and lead to domestic unrest. In a worst case, demographic trends in the wrong direction, between blocs that oppose one another geopolitically, can erode global nuclear stability.
Evaluating these effects is part of actuarial science, applied macroeconomics, and geostrategic analyses. There is nothing simple about the implications for the United States’ nuclear posture.
It is true that demographic effects may give the United States an advantage over adversaries on the economic and conventional military fronts through such things as maintaining a stable population, particularly in working- and military-age males. When demographic trends are unfavorable, the importance of nuclear weapons for the United States or an adversary grows as a smaller population of military-age males forces a nation to rely more heavily on a nuclear arsenal.
Conflicting Demographic Trends
Russia and China are suffering significant declines in their total fertility rate (TFR), that is, the average number of live births over the lifetime of each woman in their population. Ignoring the effects of immigration, so is the United States.
For a country to avoid a population gradually shrinking, it must maintain a TFR of at least 2.1. The fertility rate of the US is currently 1.6, China 1.1, and Russia 1.4. China and Russia are lower than America’s by enough to create a more serious problem for Russia, and especially for China, than for the United States. It can take decades for a state’s TFR to effectively reverse a downward trend.
The United States’ 1.6 TFR would, by itself, make the US average age increase, while also shrinking the total population. But, America has one problem which is also an opportunity, while China and Russia have only the problem—immigration. Millions of young people are trying to get into the US, legally or illegally. Very few people of any age are trying to get into Russia and China, while many people in those authoritarian regimes are leaving.
Macroeconomic and Geostrategic Effects
As a country’s population ages, the size of its working-age population declines, and so will government tax revenues. The number of young people available for military service also declines. This has negative consequences. An aging population, when not offset by youthful immigration, leads to increases in the medical and pension costs for the elderly. These costs can grow into an increasingly divisive burden on a state’s economy and citizens—reducing resources available for military expenditures.
An aging population, if not offset by immigration, also leads to a decrease in available military manpower. This can weaken conventional armed forces.
Nuclear Risks
The negative impacts of an aging population can have an unfortunate two-fold effect. They can nudge an expansionist regime to rely more on its nuclear arsenal for coercion and deterrence. In the extreme, nuclear employment “escalate to win” may occur when a smaller and less capable conventional force cannot win outright.
One reason population decline can lead to greater reliance on nuclear weapons is the economic necessity that a small conventional military creates. Nuclear weapons are a cost-effective deterrent and useful for coercion. It should come as no surprise that Russia is substituting nuclear capability for its conventional weakness.
Conclusion
The declining populations of Russia and China are a reality that is unlikely to change. Such decline has widespread impact on the economy and military. It can lead their leaders to feel pressed to rely more heavily on nuclear weapons and take aggressive action before the decline takes its full effect. The timing of the current war in Ukraine may, in part, be a result of such considerations. It appears the reliance on nuclear weapons is underway. For Russia and China, nuclear weapons are the offset to American power.
While the demographic trends mentioned can give the United States a relative advantage in the economic and conventional military spheres, it is critical the nation does not become complacent. Properly understanding these trends can emphasize how vital it is the US modernizes and right sizes its nuclear arsenal for effective deterrence.
Joe Buff is a Senior Fellow at the National Institute for Deterrence Studies (NIDS). He is an experienced actuary researching modern nuclear deterrence and arms control. The views expressed are his own.
About the Author
Joe Buff
Joe buff has long experience researching practical applications in math and actuarial science, management consulting, and national defense. His award-winning publications include six best-selling submarine technothrillers (the Captain Jeffrey Fuller series), and numerous articles and op-eds about undersea warfare, geostrategy, and nuclear deterrence in The Submarine Review, American Submariner, the U.S. Naval Institute Proceedings, The Day (New London) and on Military.com’s DefenseTech blog. Joe has presented to the Naval Submarine League, the U.S. Submarine Veterans, the U.S. Submarine Museum (Groton) and the New York State Military Museum (Albany). In early 2024 Joe was a guest on ANWA’s NucleCast, hosted by Dr. Adam Lowther, and he has begun authoring and coauthoring articles for the National Institute for Deterrence Studies' Global Security Review.
