During the coming decades, it may become increasingly difficult to induce Americans to help defend any of the increasingly numerous countries with birth rates far too low to replace their population, even if a country in question is democratically governed.

There is scant evidence that a country’s having a birth rate far lower than is needed to replace itspopulation now diminishes Americans’ willingness to help it defend itself. US Senator JD Vance, speaking on the Senate floor on February 12 to oppose further US military aid to Ukraine, pointed out that “not a single country – not even the US – within the NATO alliance has birthrates at replacement level.” But did not mention Ukraine’s birth rate, which is lower than that of any NATO country save Malta.  

However, American pundit David P. Goldman, in essays about Taiwan and Ukraine published by Asia Times in October 2021 and January 2022, suggested that those polities’ very low birth rates might warrant limiting Western military support for them. That may be a harbinger of things to come.  

The global demographic predicament   

In recent decades, the birth rate of nearly every country in the world has fallen. Nothing suggests that this trend might be reversed in the foreseeable future.

Starting in the 1970s, more and more rich or middle-income countries have come to have total fertility rates (a TFR is the average lifetime number of live births per woman) much lower than are needed to replace the population. Save for Israel and Saudi Arabia, no rich country now has a TFR above 2.1, which is the rate needed for population replacement if child mortality is low and the female proportion of live births is not artificially diminished.

Countries with TFRs now near or below 1.3 are concentrated in East Asia and southern and eastern Europe.  They include:

• Bosnia and Herzegovina, Cyprus, Italy, Jamaica, Japan, Spain and Thailand (TFRs of about 1.3);
• Ukraine, China, Malta, and Macau (1.2 to 1.1); and
• Singapore, Taiwan, Hong Kong and South Korea (1.0 to 0.7).  

Many other counties – including the Western Hemisphere’s Canada and Chile and Europe’s Albania, Austria, Belarus, Croatia, Finland, Germany, Greece, Hungary, North Macedonia, Norway, Poland, Portugal, Russia, Serbia and Switzerland – now have TFRs of around 1.4 or 1.5.

In 2022, only one continent, Africa, had a TFR above 2.1. Africa’s TFR was about 4.2; Oceania’s about 2.1; Asia’s about 1.9; Latin America’s about 1.8; Northern America’s about 1.6; and Europe’s about 1.5.

Some of the socio-economic benefits of fertility decline to a below-replacement level – notably freeing more women to work outside the home, and either reducing expenditures on child-raising and education or enabling children to be better-educated at no additional cos – ensue immediately or quickly.

In contrast, the adverse effects ensue with a lag of 20 or more years. One such effect is ever fewer people of military age and working age.

Another is a decades-long increase, to a lastingly higher level, in the elderly population relative to the working-age population and hence in the share of GDP spent on pensions and care for the elderly. For decades, people too old to work also increasingly outnumber people too young to work, so the working-age proportion of the population shrinks, despite a declining below-working-age proportion of the population.

Only countries that already had low fertility in the 1990s are now suffering these lagged adverse effects.   

However, with each passing year, these adverse effects afflict more and more countries and afflict many countries more and more strongly. As they become more widespread and acute, it becomes harder not to view peoples with persistent far-below-replacement fertility as committingcollective suicide.

Their collective suicide is largely the result of individuals’ choices. No country’s government save China’s has sought to reduce fertility to far below the population-replacing level, and the fertility-reducing effect of China’s “one child policy” dwindled to insignificance over the 36 years of its implementation. No increase in Chinese births followed its termination in 2015. As the Chinese grew richer, they wanted far fewer children – just as folks in Hong Kong, Macau, Taiwan, Singapore, Korea and Japan had previously.

Collective suicide by far-below-replacement fertility is not easily halted. In order to stabilize the population of a country that has long had such low fertility, its working-age adults must raise an average of two children per woman while providing pensions and medical care for relatively numerous old people. Absent some more efficient way of raising children or supporting the elderly, a heroic future generation of people would have to work more or consume less of their incomes than their now-living forebears, who have proven unwilling to raise two children per woman despite having relatively fewer old people to support.

This collective suicide also will become ever-harder to prevent by immigration. Sub-Saharan Africa, projected to have nearly half the world’s population by the end of this century and a growing majority of it during the 22^nd century, is the only prospective source of enough immigrants to alleviate substantially the population decline of the rest of the world at current rates of fertility. However, to absorb sub-Saharan Africans into Asia and Europe as fast as is needed and in the numbers needed seems prohibitively problematic in diverse respects.

At China’s present fertility rate, China’s birth cohort will shrink by half every generation. To offset even half that loss with immigrants from sub-Saharan Africa would make China’s population mostly African in less than three generations. That this could happen peacefully and productively seems dubitable.

Moreover, democracy does not prevent peoples from committing collective suicide by low fertility. Italy, Spain, Japan, Taiwan and South Korea have had both democratic governance and far-below-replacement birth rates for decades.

South Korea has the world’s lowest TFR, now reportedly about 0.7, only one-third of the rate needed for population replacement. By contrast, North Korea, no paradigm of democracy, is thought to have a TFR of about 1.8.  Even though North Korea’s population is only half as large as South Korea’s, its birth cohort already is larger than South Korea’s, which implies that in 20 years, North Korea will have more military-age people than South Korea. Thereafter, absent change in their relative fertility, North Korea’s military-age population will increasingly outnumber South Korea’s.

Implications for future US military aid and interventions

Since the late 1940s, US military interventions in foreign lands and large-scale foreign military assistance by the US to other states have been most easily sold to US voters when they could plausibly be presented as required by international solidarity in defense of democracy.

Consequently, US proponents of such intervention or assistance have routinely tried to present it as defending or spreading democracy, even when this strained credulity. The Kennedy, Johnson and Nixon administrations tried to present successive governments of South Vietnam as democratic, both before and after abetting, in 1963, a military coup that assassinated the leader of one such government.

In and after 2003, George W. Bush’s administration committed US forces to remaining in Iraq and creating a democratic government of that country; that failed due to hostility between Shi’ites and Sunnis, as observers including former Secretary of State Albright had publicly warned that it would. From 2001 to 2017, successive US administrations tried to persuade Americans that a sustainably democratic government of Afghanistan could be and was being created.  In 2021, that was shown to be nonsense.

However, to argue that international democratic solidarity requires Americans to spend blood or treasure to defend foreign countries with persistently far-below-replacement birth rate may in the future increasingly strike Americans as tantamount to arguing that America is ideologically obligated to enable its friends to commit collective suicide democratically rather than undemocratically. Such an argument may increasingly fail to pass the laugh test.

Unfortunately, no one has shown how to raise birth rates without greater state coercion than Americans would either tolerate at home in the US or suggest to other counties.  Although many countries have pursued diverse pro-natalist policies during the past half-century, none has succeeded in raising birth rates much. Consequently, the US cannot demand that other countries raise their birth rates as a condition of continued US alliance or support.

The TFR of the US itself, stable at around 2.1 for two decades after 1990, has fallen to below 1.7 during the past decade. Even at this level below-replacement fertility, if sustained, will tend to weaken the US economically and militarily, unless offset by diversely problematic mass immigration. This troubles not only JD Vance but also many other Americans who can’t figure out how to reverse fertility decline in their own country, much less elsewhere.

Furthermore, to re-base arguments for US foreign military assistance or intervention on fear of geopolitical threats, rather than on international democratic solidarity, may become more difficult in a world in which now-threatening countries are in steep demographic decline. Russia and China, now perceived by Americans as the most fearsome foreign powers, are both afflicted bylow birth rates.  Fear of these countries, even if warranted now, may seem ever-less-warranted to US voters by mid-century when, absent large increases in fertility, they will be imploding demographically.

A more plausible candidate for the greatest perceived international threat in the mid- and late 21^stcentury may be unwanted emigration from demographically exploding and still poor sub-Saharan Africa. Fear of that might be shared by American, Asian and European countries with diverse forms of government, engendering migration-restrictive cooperation that transcends differences of political ideology.

National fertility trends over recent decades suggest that, absent development of effective and acceptable means to control and limit fertility decline, every country outside Africa except Afghanistan, Israel, Samoa and the Solomons will suffer population aging and decline by the end of this century.

However, it’s an ill wind indeed that blows no good at all.  The proclivity to pro-democracy war-waging that has survived bloody failure in Vietnam, Iraq and Afghanistan might not survive this depopulation.  

In a world in which all non-African peoples are dying, the only good reason for any of them to war with any other would be to reduce non-productive expenditures by conscripting old-age pensioners as front-line infantry – not to defend or spread a form of government. In such a world, Westerners might return to the millennia-old pragmatic wisdom pithily versified byAlexander Pope in 1733:

For forms of government let fools contest;
Whate’er is best administer’d is best.

“Ichabod” is a former US diplomat.