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World population, world health and security: 20th century trends
  1. A Bashford
  1. Alison Bashford, School of Philosophical and Historical Inquiry, Building A14, University of Sydney, NSW 2006, Australia; Alison.bashford{at}


The connection between infectious disease control and national security is now firmly entrenched. This article takes a historical look at another security issue once prominent in debate on foreign policy and international relations, but now more or less absent: overpopulation. It explores the nature of the debate on population as a security question, and its complicated historical relation to the development of world health.

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In 2006 I was asked to speak on the history of infectious disease control to a symposium on “Security” run by the Association of Pacific Rim Universities. It was no surprise that infectious diseases were on the agenda, since under a recently broadened conception of security, democratisation and health are linked with political and social stability: infectious disease and its management now lie as much in the field of security studies as in public health, no matter how problematic this is for some participants and scholarly commentators.1 But there was another aspect of the agenda that intrigued me rather more, as a historian: population was entirely absent. This intrigue sprang not from any sense that population should have been on the agenda in 2006, but from knowledge that it would have been, if the meeting on security had taken place in earlier decades.

Engaging the past with the present typically leads to one of two positions for a medical historian: either there is a need to argue the longevity of issues that are often mistakenly understood to be entirely novel (the longstanding link between security and disease control, for example); or there is a need to explain how matters once taken for granted became entirely unfamiliar. The question of population and security belongs to the latter response. For much of the 20th century, population growth was considered one of the world’s foremost security issues, since many experts considered the disparity in population density between nations as the fundamental cause of war. As such, it would have been inconceivable not to discuss the issue at a meeting dealing with “security” in previous generations. In 2006, however, just how population could be a security issue was the inconceivable matter. In what follows, I will explain the population-security link so dominant for much of the 20th century, and explore its complicated historical relation to the development of world health.


The massive demographic changes of the 19th and 20th centuries are well known, even if their causes and effects remain under constant demographic and historical debate.2 Rapid population growth in Europe (144 million in 1750 and 594 million in 1950) was later matched by a drop in mortality rates and consequent increase in population growth rate in Asia (475 million in 1750 and 1272 million in 1950). At the same time, demographers, epidemiologists and economists from the late 19th century onwards, noted the fairly sudden drop in the birth rate, first in France (from 32 births per 1000 people in 1800 to 25.8 per 1000 by 1880).3 Typically, this has been taken by historians to mean that so-called depopulation was the European problem, while overpopulation was the 20th century Asian problem.4 5 A closer look at scholarship on population from that period shows a different picture, however. Despite the declining birth-rate phenomenon, Europe as a whole was still often understood to be one of the “danger spots” with regard to world overpopulation.

The common argument that linked population to security and international relations was that nations would become, simply, too crowded, and that standards of living would drop in a way that created unstable social environments. Crowded people and crowded nations coveted space it was theorised by a range of demographers, epidemiologists and political scientists. Thus it was less total numbers per se that comprised the security issue, than their relation to total national area and to productive land: density. This is why Europe remained a population danger spot in the minds of so many demographers, even though we now associate overpopulation so strongly with Asia. Europe’s “density” was calculated in 1928 at a problematic 127.6 people per square mile, compared to Asia’s 65.3 per square mile.6

In the interwar years, especially, world population was addressed primarily as an economic and geopolitical concern, not a health concern. Disparity in population density and in standard of living was understood to be the primary and underlying cause of war.7 Although we associate this idea with Weimar and Nazi lebensraum or “living space” policies, in fact it was typically and strongly argued by many in the field. As US demographer Warren Thompson put it in 1929, the question was one of population pressure: “Will the efforts to equalize pressures result in war or will some other method of adjustment be found?”8

It was this version of the population problem that explains the constant place of the issue at the table of international relations. The 1937 International Studies Conference of the League of Nations, to take just one example, was dedicated to the theme of “Population and Peace” under which was discussed collective security, the prevention of war, the concept of overpopulation, emigration and colonial population “carrying-capacity.”9 And this link between population and security was sustained over the second world war as well. Within the early United Nations, for example, “population” was not dealt with by the World Health Organization, but by UNESCO under its International Tensions Project. Most significantly, several generations of thinking on population pressure in relation to the first and second world wars began to take a new shape in the “Cold War,” with US foreign policy links between population, economic development and anti-communism. Overpopulation and poverty were understood to feed the potential for communist organising, and a fast-track manufactured “demographic transition” to a lower birth rate became official US policy for many developing nations and regions.10


At the same time as national disparities in population density were discussed as a central aspect of international relations, another strand of discussion on population and security emerged that was more supra-national than inter-national: the sustainability of global rates of increase. Rather like the current urgency of climate change debate, earlier generations discussed world overpopulation in catastrophic terms: not just war or peace, but incapacity of the planet to sustain the species. It was not just nations that were overcrowded but the globe. Statistician and neo-malthusian Sir George Knibbs wrote as early as 1911: “The limits of human expansion are much nearer than popular opinion imagines...the exhaustion of sources of perilously near.”6 And in 1920, birth control lobbyist and organiser of the Geneva World Population Conference Margaret Sanger, warned that “the world faces its greatest crisis. It approaches the greatest disaster of all time.”11 She, like so many others, was remarkably unconcerned about recurring influenza and far more concerned with the problem of world overpopulation and threatened global famine.i

Although we often place the “population bomb” idea in the post second world war period, estimates of world population increase were being tallied remarkably often from the earliest years of the 20th century. Liverpool social scientist and major figure in interwar demography Alexander Carr Saunders, for example, drew constantly on figures from the International Institute of Statistics and the League of Nations, estimating world population at 2000 million in 1930. But of course it was the rate of growth over the 19th and 20th centuries that alarmed so many, as they projected unsustainable numbers usually around the year 2160.12


How was the problem of world overpopulation part of the organisational and political history of world health? The most important finding is that for much of the century, it wasn’t. Within the League of Nations population was not an issue that fell to the Health Organisation, the interwar precursor of the World Health Organization, but to the league’s economic section. Several minor attempts by the League of Nations Health Organisation and the early WHO to incorporate or even mention family planning, failed. When, in 1931, Dame Janet Campbell headed a report on maternal health and welfare, which included a paragraph recommending women’s avoidance of conception if pregnancy would entail a risk to their own health, the Health Organisation was swiftly silenced by Catholic member-states in the assembly.13 And despite early 1950s efforts to put contraception and family planning on the WHO agenda, it was not until the very late 1960s that it became firmly part of that organisation’s remit.

It took a long time, then, for the reproductive and sexual health understanding of the world population problem to emerge in the arena of international health. Agencies typically sidestepped the question of birth control because so many member governments questioned its legal and ethical status, because Fascist states held such strongly pro-natalist programmes in the period, and because Communist states opposed ideologically the malthusian linking of overpopulation with poverty. This avoidance was also a measure of the other terms in which the population problem was understood: as a question of economics, food production, access to land and migration.

Population became a world health issue almost despite the official intergovernmental organisations. Much more significant was the work of several national governments in implementing population-reduction policies.14 India took the lead. There was a dramatic decline in the death rate in India after independence from 27 per 1000 in 1947 to 14 per 1000 in 1968. But this meant that the annual growth rate in India increased sharply from 1.4% in 1948 to 2.5% in 1966.15 It was a trend and a problem noted early. From 1935, Jawaharlal Nehru, the Indian National Congress and the All-India Women’s Conference had stressed the need for family planning to be an integral component of India’s developmental plans.16

Gradually, other national governments pressed the United Nations (and WHO) to provide technical assistance for contraception and family planning programmes. The pressure was regional as well. After the 1955 Bandung Conference of the Economic Commission for Asia and the Far East, significant pressure was placed on the UN Assembly to endorse and fund practical programmes. This led to the Asian Population Conference of 1963 in New Delhi, which unanimously recommended that regional governments seek practical assistance and action programmes from the agencies, including WHO, thereby contributing to economic development. And in 1968 the World Health Assembly endorsed family planning as a basic component of primary health care.17

By the late 1960s, population was on the cusp of being understood primarily as an issue of women’s health, sexual health and development: the terms in which we most clearly identify the problem today. But what needs to be recognised is that population became a world health issue at least as much because of concern about mortality trends as fertility trends. It was a standard argument to link developments in public health and infectious disease control to increasing rates of population growth for the world as a whole. When the influential director of the US Planned Parenthood Federation, William Vogt, tried (and failed) to persuade WHO director Brock Chisholm to include population control on WHO’s agenda in the early 1950s, he did so in telling terms. Vogt argued not on the basis of women’s health or sexual health, but through the question of malnutrition:

Since the pathological condition that we call malnutrition is . . . the result of the death rate falling more rapidly . . . and since this fall in death rate is a direct function of applied medicine and public health, the cure of malnutrition would seem to come within the purview of the WHO. . .Unless an attempt is made to reduce the demand as well to increase this supply [ie of food], it would seem to me as a biologically trained layman that only half an attempt is being made to cope with the disease of malnutrition.18


This all augmented the work of US philanthropic foundations like Rockefeller, Carnegie and Ford, which had longstanding interests in health and welfare measures and which were influential in the US government’s uptake of population control as an anti-communist measure. Major players like Henry Kissinger were talking with the foundations about the population problem since, for successive US governments in the Cold War, curbing population growth in the developing world was high on the security agenda. Under pressure from the United States, including financial pressure of funds tied to family planning, most of the UN agencies including WHO eventually came to take on distinctive roles in world population planning, policy and technical assistance on contraception.

Historians sometimes assess US foundation and US government intervention into world population policy as solely political in the sense of anti-communist, or as an extension of interwar eugenic practices on a global scale. There is substance to this in cases like Puerto Rico and India.19 20 But the foundations also inherited the longstanding neo-malthusian concern about planetary sustainability, stretching back at least to the beginning of the 20th century. As Paul Henshaw of the Atomic Energy Commission in Japan (1946–7) put it to the initial meeting of the Rockefeller’s Population Council in 1952: “The endocrinologists, gynaecologists and students of human reproduction are very much of one mind on population. They see it as the world’s basic problem and feel that the prospects for peace and long-range progressive development of human welfare are dependent upon the satisfactory resolution of it.”21 The connection with war, peace and security still figured centrally, but it was bioscientists rather than political scientists who were increasingly placed centre-stage.


As a problem for political, economic and health experts, world population has had a strange 20th century history. For many years after the first world war population “security” was understood to be about density and distribution of people. By the time the Indian government (after 1947) and the US government and foundations (in the late 1950s and 1960s) took up the problem, the possibility of significantly reducing rates of growth began to dominate implementation strategies. This was when world population started to be understood more as a health issue than a geopolitical and economic issue. Or more correctly, health interventions were the means by which the political and security problems (still) associated with overpopulation could be addressed. By the 1970s, however, the security aspect of the population problem began to drop away, and the paradigm shifted to a more individualistic politics of human rights and consent, of access to primary health care and of women’s status and development.

The current world population is 6600 million.22 This far exceeds early 20th century predictions, which typically estimated the apparently catastrophic number of 3900 million in the early 21st century.5 And yet world overpopulation barely registers now as a political issue let alone a security issue. The links between population and international relations have dropped away almost entirely. In part this is structural: the rate of world population growth has declined from a peak in 1963 (2.3%) to the current figure of just over 1%, attributed to contraception and to later marriage and childbirth.23 In part, the geopolitics, economics and technology of food production and exchange have altered massively over the 20th century, resulting not in famine for the globe as predicted, but localised famine. But the changing politics of world population is also partly because it was increasingly taken up by the health sector in the latter half of the 20th century. Once lodged as an issue of individual women’s and parents’ choices about conception and pregnancy—that is, as “reproductive health” rather than as “population”—the geopolitical and security implications are minimised. To observe this is not to diminish the importance of women’s health and/or sexual health. It is to note both the trends and the effects of such a change.

“Paradigm shifts”—which always happen over time—are as much on historians’ radars as they are on post-Kuhnian scientists’. In the case of world population something amounting to a paradigm shift took place over the 20th century, less with respect to rates of growth themselves, than with how that growth became a social-scientific, biotechnical and a political problem. This alerts us to the nature of current debates on security, world health and population: what are the terms in which the problem is conceptualised, or is there no longer a world population problem? Curiously, the latter might be more on the mark than it first appears in the sense that population growth is becoming less problematised. There are signs that (over)population even as a health issue is on the wane. It is as absent from the agenda of the WHO Commission on Social Determinants of Health as it is from the UN Security Council, for example.24 And the problem of world population growth is a lesser part of the climate change debate than might be expected; the connection between energy and population was far more twinned in both popular and scientific circles as recently as the 1980s, and was certainly so for a group like the Population Council in the 1950s. While the primary purpose of this historical article is to reveal the nature of the significant 20th century trends in the politics of population, security and health, this all signals a complicated history of current global issues, not just in how the population-health-security nexus is present, but perhaps more significantly where and how it is (becoming) absent.



  • Funding: This research was funded by the Australian Research Council.

  • Competing interests: None.

  • iIt was growth in world rates as much as national or regional rates that exercised many at a string of international meetings on the issue. This historical research is based on the published proceedings and the unpublished organisational records of world population conferences from the International Neo-Malthusian Conference of 1910 to the UN World Population Conference in Bucharest in 1974, and on League of Nations and UN agency archival records.

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