As American policymakers stand at the beginning of the 21st century, they tend to view weapons proliferation, hypernationalism, ethnic and tribal conflict, political repression, and protectionism as the principal threats to the open, liberal international order they are trying to create. All of these factors are indeed dangerous and worthy of attention, but the risks posed to U.S. security interests around the world by demographic factors must not be neglected either. The dynamics of population growth, settlement patterns, and movement across borders will have an effect on international security in the upcoming decades, and Washington can do much to solidify its geopolitical position in critical regions by anticipating demographic shifts that have security implications and by working with allies, friends, and international organizations to deal effectively with the causes and consequences of these shifts.
The nature of the future international security environment will be determined by complex interactions between geopolitical alignments, technological advances, economic developments, demographic factors, and environmental trends. It is not the intention of this report to explain or even map out these interactions, as that would be far beyond our scope. However, it is clear from even a cursory analysis of the national security literature on demographic effects that population pressures and movements by themselves do not cause armed conflict; rather, demographic shifts occurring in political environments that are already tense as a result of territorial disputes, ethnic rivalries, ideological divides, environmental stresses, etc., can very often be just the right spark needed to transform a tense situation into a violent conflict or perhaps even outright war. Demographic factors therefore need to be viewed by the analyst as a potentially important contributor to armed conflict, one that interacts with other variables in a complex series of linkages and feedback loops to cause the tensions that are often precursors to political violence.
Clearly, demographic issues and concerns have weighed on the minds of policymakers and scholars throughout the modern era, so it is legitimate to pose the following question: Why do the security dynamics of demographic factors merit consideration now, at the outset of the 21st century? The simple answer to this question is that there are a number of current trends that heighten the importance of the demographic-national security nexus. The end of the Cold War has forced security analysts to widen their scope of thinking both functionally and geographically as broadened notions of the threat to U.S. interests have come to the fore. Furthermore, increasing globalization in the form of rapidly multiplying mass communications links (satellite TV, Internet, etc.) has made it more difficult for American leaders to ignore demographic-induced instability in even remote regions of the world. Accompanying these broadened notions of threat has been an increasing focus within the U.S. military on nontraditional missions such as peacekeeping and humanitarian assistance, missions that are sometimes required because of demographic factors such as sudden refugee movements. Finally, one sees increasingly stark differences between the demographic profiles of high- and low-fertility nations, the implications of which have yet to be fully explored. However, one can hypothesize that these diverging trends will have some impact upon the views of both developing and developed nations toward different options for achieving security.
This report has three objectives. The first, and most important, is to lay out a general framework for looking at population developments through the prism of security issues. It is hoped that such a framework will serve the purpose of facilitating a constructive dialogue between professional demographers and national security policy analysts who have become interested in the security implications of population growth, decline, and movement. Second, the report will try to make some very preliminary assessments as to which demographic trends/factors might threaten U.S. interests around the world. Third and finally, some basic recommendations for U.S. policy will be offered in light of the emerging demographic realities.
What Do We Mean By "Demography"?For the purposes of our discussion here, demography is defined as consisting of two basic areas: population composition and population dynamics.
Population composition has to do with descriptions of the characteristics of a given population (whether of a nation-state, a province, or an ethnic group). Populations can be described through the use of parameters such as size, age distribution, geographic distribution, ethnic/religious makeup, and level and distribution of human capital.
Population dynamics deals with changes in the composition of a given population over time. These changes could take place in either size or relative proportions of different subgroups. The two main instruments for population change are natural increase or decrease (births minus deaths) and migration (either internal or international).
The balance of this report is divided into four chapters. Chapter Two is a short review of the evolution of Western intellectual views on population as a national security variable, by which we hope to create a frame of reference for judging current population-related national security issues. Chapter Three presents some of the key demographic trends at work in the world today. Chapter Four places the various security implications of demographic factors into a framework that emphasizes their effects on the nature of future conflicts, the sources of national power, and the sources of conflict. Finally, Chapter Five concludes the report with a brief discussion of policy implications for the United States.
 For a late Cold War view of demographic effects on security issues, see Sam C. Sarkesian, "The Demographic Component of Strategy," Survival, November/December 1989, pp. 549-564.