Walking in Beijing, January 2024
Tingshu Wang / Reuters In the decades immediately ahead, East Asia will experience perhaps the modern world’s most dramatic demographic shift. All of the region’s main states—China, Japan, South Korea, and Taiwan—are about to enter into an era of depopulation, in which they will age dramatically and lose millions of people. According to projections from the Population Division of the UN Department of Economic Social Affairs, China’s and Japan’s populations are set to fall by eight percent and 18 percent, respectively, between 2020 and 2050. South Korea’s population is poised to shrink by 12 percent. And Taiwan’s will go down by an estimated eight percent. The U.S. population, by contrast, is on track to increase by 12 percent.
People—human numbers and the potential they embody—are essential to state power. All else being equal, countries with more people have more workers, bigger economies, and a larger pool of potential soldiers. As a result, growing countries find it much easier to augment power and extend influence abroad. Shrinking ones, by contrast, struggle to maintain their sway.
East Asian countries will be no exception: the realm of the possible for its states will be radically constricted by the coming population drop. They will find it harder to generate economic growth, accumulate investments, and build wealth; to fund their social safety nets; and to mobilize their armed forces. They will face mounting pressure to cope with domestic or internal challenges. Accordingly, Japan, South Korea, and Taiwan will be prone to look inward. China, meanwhile, will face a growing—and likely unbridgeable—gap between its ambitions and capabilities.
Because of the effects on China, East Asia’s loss promises to be Washington’s geopolitical gain. But the drag on East Asia’s democracies will create problems for Washington. These states will become less attractive partners for the United States, just as their need for partnership with the United States grows. The U.S. government might then come under pressure to invest less in these countries’ security, generating friction that American officials will have to manage carefully to protect Washington’s alliances.
There is more to national power than head counts, of course. But depopulation will disadvantage East Asia’s states in ways that will become increasingly difficult to overcome. Demography is not destiny, but the power of demography means the long-heralded “Asian century” may never truly arrive.
INFLECTION POINT
In the decades after World War II, East Asia’s population boomed. Between 1950 and 1980, it increased by almost 80 percent. By 2020, the region had almost 2.5 times as many inhabitants as in 1950, growing from under 700 million to almost 1.7 billion. This population leap far exceeded the United States’ own total growth over those three generations, and it occurred faster. It was integral to East Asia’s extraordinary economic takeoff.
But even as East Asia’s population rose, the underlying trend lines presaged a coming decline. In Japan in the early 1970s, fertility fell below the replacement level, which is generally defined as 2.1 births per woman. In the 1980s, the same thing happened in South Korea and Taiwan. China—the giant that accounts for five-sixths of East Asia’s total population—followed suit in the early 1990s. Since then, the region’s fertility has fallen even farther below replacement. As of 2023, Japan is East Asia’s most fertile country, even though its childbearing levels are over 40 percent below the replacement rate. China’s childbearing levels are almost 50 percent below the replacement rate; if that trend continues, each rising Chinese generation will be barely half as large as the one before it. Much the same is true for Taiwan. South Korea’s 2023 birth level was an amazing 65 percent below the replacement rate—the lowest ever for a national population in peacetime. If it does not change, in two generations South Korea will have just 12 women of childbearing age for every 100 in the country today.
East Asia, in other words, is set on a course of decline that extends as far as the demographer’s eye can see. The region is set to shrink by two percent between 2020 and 2035. Between 2035 and 2050, it will contract by another six percent—and thereafter by another seven percent for each successive decade (if current trends hold). The depopulation extends beyond East Asia’s four main countries to their northern neighbor—Russia—where population is projected to decline by about nine percent between now and 2050. (Populations will change fractionally in Mongolia and North Korea, too, but those two countries today account for less than two percent of East Asia’s population.)
This is not the first time East Asia has lost inhabitants. According to historical records, China has undergone at least four long-term depopulations over the past two millennia. Some of these bouts lasted for centuries. After AD 1200, for example, China’s population shrank by more than half. It took the country almost 350 years to recover. Japan and Korea also endured long-term depopulations before they began modernizing.
But the impending depopulation is different from all the ones before it. In the past, East Asia’s (and every region’s) prolonged contractions were a consequence of dreadful calamity—such as war, famine, pestilence, or upheaval. Today, the decline is taking place under conditions of orderly progress, improvements in health conditions, and spreading prosperity. The coming depopulation, in other words, is voluntary. It is happening not because people are dying en masse but because they are choosing to have fewer children. China provides perhaps the starkest illustration of this fact. The country suspended its coercive one-child policy in 2015, yet in the years since, annual births have fallen by more than half.
Current East Asian fertility patterns could change; demographers have no reliable tools for predicting long-term fertility trends. But there has never yet been an instance of a country where birthrates fell 25 percent below replacement and then rebounded to replacement levels, even temporarily. It will, therefore, not resemble past depopulations, where high birthrates restored population once famine, war, or other disasters subsided. After decades of sub-replacement fertility, East Asia’s trajectory of population loss has been largely baked into the cake for decades to come.
East Asian demographic patterns stand in sharp contrast to those in the United States. Unlike that of East Asia, the U.S. population is still enjoying growth in both total numbers and its 15‒64 cohort. It is still tallying more births than deaths, despite high rates of illness compared with other rich Western societies. Death totals in the United States have been rising steadily over the postwar era, but death rates are not projected to outpace birthrates until the early to mid-2040s. The country’s birthrates are below replacement levels, but U.S. fertility is nonetheless over 40 percent higher than East Asia’s. The United States also attracts high numbers of immigrants, bolstering its population, whereas immigration is negligible in East Asia. It is impossible to forecast whether large-scale international migration into the United States will continue, but if it does, the country will continue to grow for decades.
GOING GRAY
Given that a very large share of East Asia’s 2050 population is already alive, demographers can speak about the outlook for the region’s countries with a high degree of confidence. What they have to say does not sound especially positive. By 2050, the population in every one of the region’s countries will be smaller and older than it is now. The China of 2050, for example, will have many fewer people under 60 than does today’s China. But it will have two and a half times as many septuagenarians, octogenarians, and nonagenarians as today—another 180 million of them—even though the country’s total population will decline. In other countries, the changes will be even more drastic. In 2050, Japan will likely have fewer people than it does today in every age cohort under 70. Taiwan will have more people over 75 than under 25. In South Korea, there will be more people over 80 than under 20.
This demographic shift will cost these countries more than just their youth. It also threatens to sap them of economic vitality. As a rule of thumb, societies with fewer people tend to have smaller economies, as do societies where the elderly make up a disproportionate share of the population. The elderly work less than the young and the middle-aged: there is a reason why demographers conventionally refer to people between 15 and 64 as the “working age” population. And although East Asia’s working-age cohort grew until 2015, the region’s labor pool is now shrinking. If projections hold, China’s working-age population will be more than 20 percent smaller in 2050 than in 2020. Japan’s and Taiwan’s will be about 30 percent smaller, and South Korea will be over 35 percent smaller.
In theory, East Asia could surmount this demographic disadvantage by jump-starting labor productivity. But there is no easy policy mechanism by which these states can accelerate worker efficiency, and East Asia’s depopulation will make it even harder for workers to increase national per capita output. The region’s “potential support ratios”—that is, the number of people who are between 20 and 64 relative to those who are 65 and older—are expected to plunge in the years ahead. In 2020, that ratio was 5.1 to 1 for China, 4.4 to 1 for Taiwan, 4.2 to 1 for South Korea, and 1.8 to 1 for Japan. In 2050, it will be 1.8 to 1 for China, 1.4 to 1 for Taiwan, and an almost unfathomable 1.2 to 1 in Japan and South Korea—meaning that, in Japan and South Korea, there will be almost as many people over 65 as between 20 and 64. This transformation will likely depress individual productivity, savings, and investments, as workers and their parents devote ever more time and money to elder care. It will also cost governments, which will have to figure out how to increase spending on social welfare—in particular, on pensions and health care—even as economic growth stalls.
The economic crunch from graying and shrinking can be mitigated through healthy aging, more and better training and education, higher workforce participation, and longer careers. But states have only so much leeway to squeeze out more from less. And like it or not, the fastest-growing age demographic in these countries is likely to be the one least able to work: people over 80. In China, this “oldest old” contingent will more than quadruple between 2020 and 2050. By midcentury, one in ten of the country’s people will be an octogenarian or above. In Japan and South Korea, nearly one in six will be over 80 years old. By 2050, all of East Asia will have more people over 80 than children under 15. (In South Korea, there could be twice as many.) The United States will be aging, too, but will have a lower share of super-elders in 2050 than any East Asian country. This contrasts with 1990, at the end of the Cold War, when the United States had a higher share than any of them.
Many of these super-elders will have few kin to care for them—or none at all. East Asia has the highest childlessness levels of any region on the planet today. Japanese demographers estimate that a Japanese woman born in 1990 stands an almost 40 percent chance of never having children—and slightly better-than-even odds of never having biological grandchildren. By 2050, over a sixth of Chinese men in their 60s will be so-called surplus boys from the days of the one-child policy who never married or had children.
Exactly how old-age support will work in societies so bereft of descendants is a question that has typically been relegated to dystopian science fiction treatises. But now, those stories are looking a little less fantastical. In the 2022 Japanese film Plan 75, Tokyo has started paying seniors to euthanize themselves as a way to reduce their economic toll on society. When the director, Chie Hayakawa, was crafting its main character, she interviewed 15 elderly women—all of whom said they would welcome such a plan in real life. “It’s too real to be sci-fi,” Hayakawa said of the movie. “I specifically made this film to avoid a program like this becoming a reality.”
NO MAN’S LAND
East Asia’s population implosion is, foremost, a domestic socioeconomic challenge. But it also poses inescapable constraints on the region’s international clout. The East Asian population explosion helped produce large economies and strong militaries. In fact, it showed up in military-age men before it reached the rest of the adult population. The same will be true for the region’s fertility collapse. In every East Asian country, depopulation will hit the potential recruitment pool even faster—and even harder—than the general working-age population.
Geopolitically, this decline will benefit Washington by weakening its main rival. Between 1950 and 1990, China’s cohort of military-age men—that is, men between 18 and 23—shot up from 30 million to 80 million. Since then, it has dropped to about 50 million, and it is expected to return to roughly 30 million by 2050. When China celebrates the 100th anniversary of the Chinese Communist Party’s civil war victory in 2049, it will have scarcely more potential recruits than it did during the year of its triumph. The United States, by contrast, is projected to have more military-age men in 2050 than it did at the end of the Cold War. Back in 1990, China had almost seven times as large a recruiting pool as the United States; by 2050, it is projected to be just two and a half times as large.
This extraordinary shift will limit options for China, which will have to make difficult strategic tradeoffs concerning its precious 18-to-23-year-old manpower. The country’s supply of young adults with the highest educational attainment, the best technical skills, and perhaps the most promising human potential will have a harder time improving the country’s general global position. They will, after all, account for a smaller and smaller share of the national population than they do today. Should they go into the military, removing them from a flagging national economy? If they remain civilians, should they try to go immediately to work at the cost of long-term training? These are not the sort of calculations a rising power wants to face.
In a real military crisis, there is usually no true substitute for manpower.
What’s more, China’s remaining numerical advantage over the United States in military-age manpower may be further qualified by other demographic stressors. Beijing will have less money to spend on the armed forces if it spends more on elder care. Likewise, if China has few young men relative to its population of elders, society and the state could possibly grow more sensitive to casualties and thus more militarily risk-averse. This possibility is sharpened by the rise in the number of only children in the military’s recruitment pool.
To be sure, China will remain an enormous country with a huge economy and military force. It can hardly help but remain a formidable power—indeed, it will be difficult for China to drop out of second place. The Chinese government may also be able to compensate for some unfavorable military demography with technology, such as artificial intelligence and autonomous weapons. But in a real military crisis, there is usually no true substitute for manpower. Fielding and funding a competitive military force is about to get much harder for Beijing relative to Washington, almost regardless of what the Chinese government decides.
East Asia’s population implosion, however, will not count as an across-the-board win for Washington. The region’s other countries, after all, are shrinking as well, including states traditionally of great help to Washington. As Japan, South Korea, and Taiwan lose people, they may no longer be able (or willing) to offer the same contributions to regional security. Back in the late 1950s, for example, there were almost as many 18-to-23-year-old men in Japan as there were in the United States, making Tokyo a valuable U.S. Pacific ally. But that is now ancient history. By 2020, Japan had less than a third as many military-age men as the United States. By 2050, it could have barely a fifth. The South Korean military-age population was never as large as Japan’s, but its recruitment pool—once 25 percent as large as the United States’—was big enough to help the United States both on the Korean Peninsula and in broader planning for Northeast Asia’s defense. But by 2050, South Korea’s recruitment pool will be less than 10 percent as big as the United States’. Taiwan’s corresponding balance in relation to the United States is also falling sharply, from ten percent in 1990 to a projected five percent in 2050.
These countries will still need Washington. In fact, the United States’ economic and military potential will be more important than ever for the safety of these shrinking countries. But thanks to population declines, it will be harder for Japan and South Korea to contribute to their formal security partnerships with Washington (and for Taiwan to pull its weight in any informal arrangement). Demographics will be constantly changing the terms of trade in these friendly partnerships, shifting more burden to the United States.
Demographic trends should give Americans some hope.
It is not hard to imagine how such strains could lead Washington to curtail aid. U.S. officials already routinely complain about allied countries spending too little on defense, and none of their populations have yet to truly crater. But the United States must not fall prey to this temptation. If resentment and acrimony undermine collective security in East Asia, democracies on both sides of the Pacific stand to lose while Beijing stands to gain (even as it depopulates). U.S. officials must therefore pay attention to the demographic trends facing East Asia over the next several decades and work proactively with regional partners to address the defense burdens that lie ahead.
Provided such conversations succeed, these demographic trends should give Americans some hope—and not just because they will weaken China. The United States may be beset with domestic problems and divisions, but to the extent that demographics matter, its strategic future looks surprisingly bright. The country’s under-30 population is projected to be just slightly smaller in 2050 than today, and the overall working-age population will be larger. The country is set to gray, but much more modestly than any in East Asia. By 2050, the United States will have a higher potential support ratio than any major Western economy, with a projected 2.3 Americans of working age for every senior citizen.
The power of demography is bestowing on the United States a great strategic gift in the Asia-Pacific. U.S. policymakers and strategists would be wise to recognize the opportunity and seize it. They need to think through the ways in which this big demographic tilt should change their approach to China and the region overall—including to their friends. Doing so will help Washington best take advantage of what one might call American demographic exceptionalism.