Phases of Theory Development—"Real" World

The foundations were established by the 1980s. Until very recently the theory focused on the physical realm of traditional world politics—along with all other theoretical and empirical analysis in international relations. The construction of cyberspace created new challenges pertaining to quantification of the master variables, state profiles, and patterns of behavior. This section focuses on empirical theory and analysis in the conventional realm, a necessary prerequisite for understanding measures and metrics for the cyber domain.

In retrospect, we now appreciate that the quantitative work and empirically based inferences have evolved over time. We can now point to distinct phases, each with its theoretical and methodological features.


The initial phase, reported in Nations in Conflict, is a large-scale cross-national multi-equation econometric investigation of the 45 years leading to World War I (Choucri and North 1975). The quantitative work includes a set of models and simulations that yield empirical connections between the master variables and the behavior of states. Choucri and North developed an econometric simulation model of six major powers over the span of 45 years leading to World War I. In each case they found the causal connection between the master variables and the overt international behavior. The traditionally dominant power during this period, Great Britain, viewed any significant growth in other powers as a source of threat and these perceptions were translated into specific policies intended to retain an advantage over the other powers, most notably a rapidly growing and newly unified Germany.  The discussion of each of the equations in the overall model of jointly estimated dependent variables is contextualized in a historical narrative that enriches the analysis, the results, and the inferences drawn.

The theory of lateral pressures, then it its infancy, was readily mapped onto a set variables and processes that represented growth, expansion, intersections of interests, conflict, and violence. Below shows the logic of empirical investigation at that time. All variables, dependent and independent, other than the ultimate dependent variable, violence, were derived from existing statistical record and adjusted appropriately for comparison across countries and over time. The final dependent variable was constructed based on a 15-point international interaction scale developed for that purpose. This was long before measuring intensities of hostility in world politics became common practice in the field. In retrospect, it is clear that this study preceded the development of formally framed state profiles, as it did the quantitative articulation of the propensities for expansion, rather than the actual behavior.

Shortly thereafter, The Political Economy of War and Peace (Ashley 1980) extends the lateral pressure logic, as well as the measures and metrics, into a system of simultaneous equations representing conflict dynamics among competing powers in the post-World War II era. Ashley focused on the interactions generated by differentials in growth of population, resource access, and levels of technology focusing on the United States, the Soviet Union, and China. This book demonstrates the close interconnections among national growth, bilateral rivalry, and multilateral balance of power. It is also the first quantitative analysis of these three Powers in world politics.

The study shows how the dynamics of insecurity and the antagonizing processes contribute to the globalization of military competition which, in turn, creates serious impediments to the collective management of many dimensions of growth itself. Careful model development, empirical grounding, and parameter estimation, as well as simulation of sensitivity analysis, revealed the overall security problematic surrounding major power interactions. Despite changes in world politics since 1914, and the processes modeled in Nations in Conflict, some fundamental features of lateral pressure retained powerful resonance during the post-World War II period.

In retrospect, despite the end of communism and the dissolution of the Soviet Union, the analysis as well as the results shed important light on the emergent challenges to global and national security in the 21st century. The unquestionable dominance of the United States in world politics does little to dampen perceptions of threat due to China‘s growth given its rapid expansion in the global economy, nor perceptions of Russian threat, given its period of encroachment on the sovereignty of select neighbors.


Ashley, Richard K. 1980. The Political Economy of War and Peace: The Sino­ Soviet­ American Triangle and the Modern Security Problematique. London: F. Pinter.

Choucri, Nazli, and Robert C. North. 1975. Nations in Conflict: National Growth and International Violence. San Francisco: W. H. Freeman.

The second phase of empirical analysis of lateral pressure consists of a detailed analysis of Japan over the span of more than one hundred years (Choucri et al. 1992). Focusing on growth, development, competition, warfare, and reconstruction, this case illustrated the ways in which Japan sought to manage its resource constraints, adopt internal and external policies to meet its core demands, and find itself engaged in competition with other states-leading to conflict it viewed as essential for its survival. The concept of the state profile, introduced in an earlier study (Choucri and North 1989), was operationalized and put to the empirical test in the Japan case across three historical periods—before World War I, during the Inter-War decades, and following the Second World War. Aptly termed The Growth of Japan Before World War II and After, this empirical study grappled “before” and “after” dynamics created by sharp system breaks due to war (that is, after World War I and after World War II), as well as the subsequent transformations in the 1950s, 1960s, 1970s, and the early 1980s.

The Japan case indicates how a country‘s profile can change over time and how these changes are associated with different patterns of international behavior. Each period demonstrated different structural features and alternative pathways for adjustments to internal and external constraints. Nonetheless, Japan‘s profile continued to demonstrate powerful resource scarcities, and thus the necessary dependence on external trade. The demand for imports could only be met by the supply of exports, thus shaping a vicious cycle of reliance on external resources. Japan was caught between a rock (invariant resource levels) and a hard place (external constraints on resource access). In the decades preceding major international conflicts Japan fostered its eventual technology-dominant profile, enabling it to engage in a wide range of expansionist activities to reduce its resource constraints. The book was long completed before analysts recognized the declining birth rate of Japan and the leveling of its population growth—potentially affecting the country’s profile.


Choucri, Nazli, and Robert C. North. 1989. "Lateral Pressure in International Relations: Concept and Theory." In Handbook of War Studies, edited by  M. I.  Midlarsky. Boston, MA: Unwin Hyman.

Choucri, Nazli, Robert C. North, and Susumu Yamakage. 1992. The Challenge of Japan before World War II and After: A Study of National Growth and Expansion. London: Routledge.

The third phase of lateral pressure modeling builds on exploratory system dynamics modeling for the period from the 1970s onward, and introduces investigations based on fuzzy logic. Early system dynamics models of lateral pressure such as Choucri et al. (1972) addressed the interconnections among the master variables that create internal sources of external conflict. Extending this work, Choucri and Bousefield (1978) developed a model of the economy anchored in the master variables, and located sources of lateral pressure and propensities toward modes of external behavior.

Later, in a comparative analysis of 20 countries (industrial and developing), Wils et al. (1998) extended the analysis of internal sources of international conflict and examined the nature of the feedback effects, namely, how international conflict in turn influences and even alters the master variables of the state and changes the internal sources of conflict as well as propensities for particular modes of external behavior.  Subsequently, Lofdahl (2002) modeled the relationship between internal dynamics of growth and development rooted in the master variable, on the one hand, and propensities toward particular patterns of international trade and their environmental impact, on the other. Lofdahl’s work departed from previous investigations by adopting a worldwide perspective and positing the all-encompassing global system

This phase concentrates on basic changes in the master variables across states and over time—and implications for international relations. Introducing the use of fuzzy logic, the analysis generated empirically based distributions of states both within and across profile groups (Wickbolt and Choucri 2006). The use of fuzzy logic facilitates more systematic and more accurate specifications of the distribution of states throughout the international system. This could be an important step in visualizing shifts in state “location” over time and, to some extent, helping to anticipate conflict-prone behavior.


Choucri, Nazli, M. Laird, and D. L. Meadows. 1972. Resource Scarcity and Foreign Policy: A Simulation Model of International Conflict. Cambridge, MA: Center for International Studies, Massachusetts Institute of Technology.

Choucri, Nazli, and Marie Bousefield. 1978. "Alternative Futures: An Exercise in Forecasting." In Forecasting in international relations: Theory, Methods, Problems, Prospects., edited by Nazli Choucri, and Thomas W. Robinson. San Francisco: W.H. Freeman.

Lofdahl, Corey L. 2002. Environmental Impacts of Globalization and Trade: A Systems Study. Cambridge, MA: MIT Press.

Wickboldt, Anne-Katrin, and Nazli Choucri. 2006. "Profiles of States as Fuzzy Sets: Refinement of Lateral Pressure Theory." International Interaction 32, 153–181.

Wils, Annababette, Matilde Kamiya, and Nazli Choucri. 1998. "Threats to Sustainability: Simulating Conflict Within and Between Nations." System Dynamics Review 14, 129–162.

All of these investigations were undertaken with reference to the “real” traditional international system. Incorporating the natural environment is an important development in empirical analysis of lateral pressure theory—and in quantitative analysis generally. These studies are all informative in their own right. Each one provides important insights and evidence about internal dynamics, state attributes, external behavior and the antagonizing processes that lead to system-threatening dynamics and, in some cases, to overt conflict, violence, and war. And they all focus on the “real” international system.

Of importance in empirical analysis of lateral pressure theory are efforts to endogenize the natural environment by tracking the impacts of human activity on nature. Stated thus, the challenges become near-overwhelming. By necessity, we have selected to begin with the first principles, that is, to focus on anthropogenic sources of greenhouse gases. Early on we began to examine the specific activities that are most dominant in generating specific green gases and to take note of the salient properties of these gases. Then, we identified the states most engaged in the activities in question. This provided a “mapping” of social impacts on nature. Greenhouse gases generated in the course of creating human products and processes can be viewed as environmental lateral pressure, or lateral pressure in the environment mode. This is a propensity intimately tied to and created by the nature of products and processes—without explicit consideration of nature’s life supporting properties (Choucri and North 1993).


Choucri, Nazli, ed. 1993. Global Accord: Environmental Challenges and International Responses. Cambridge, MA: MIT Press.

The concept of sustainable development is to be an important addition to international relations theory, policy, and practice – and to the lateral pressure logic—by helping to provide system boundaries for framing the problems at hand. Mapping Sustainability: Knowledge e-Networking and the Value Chain (Choucri et al. 2007) draws on the work of Marvin Minsky—the founding Director of MIT’s Artificial Intelligence Laboratory—who posits that it is useful to think of a frame as “a sort of skeleton, something like an application form with many blanks or slots to be filled” (Minsky 1986, 245).

Focusing on the master variables as critical drivers of lateral pressure, the framing challenge is to provide the skeleton within which to fill knowledge materials central to sustainable development. Based on visualization technologies, utilizing geographical information systems (GIS) technologies, Ortiz (2007) shows the distribution of state profiles in 2-dimensional and 3-dimensional maps of the global system. These maps show the global patterns of greenhouse gas emissions, as well as the emissions by profile type. Ortiz illustrates the geographic distribution, temporal evolution, and cross-sectional inter-relationships of relevant variables, the categorical proxy of country profiles, and related variables of growth and development across all countries over a time frame of over several decades. These maps visually convey the basic message embodied in large datasets with complex inter-relationships between variables across a geographic space. Visualization contributes to our overall understanding of the lateral pressure dynamics in ways that transcend the econometric or system dynamics methodologies. In many ways, visualization can expedite the process of hypothesis generation and testing.


Choucri, Nazli, Dinsha Mistree, Farnaz Haghseta, Toufic Mezher, Wallace R. Baker, and Carlos I. Ortiz, eds. 2007. Mapping Sustainability: Knowledge e­-Networking and the Value Chain. Dordrecht, The Netherlands: Springer.

Minsky, Marvin. 1986. The Society of Mind. New York: Simon and Schuster.

Carlos I. 2007. "Visualization." In Mapping Sustainability: Knowledge e-Networking and the Value Chain, edited by Nazli Choucri, Dinsha Mistree, Farnaz Haghseta, Toufic Mezher, Wallace R. Baker, and Carlos I. Ortiz 231–260. Dordrecht, The Netherlands: Springer.

The construction of cyberspace, with the Internet at its core, creates a distinct "space" of interaction enabled and mediated by advances in information and communication technologies. With this comes an entirely new vocabulary coupled with entirely new forms and representations of realities and contingencies. These intersect and interact with the traditional modes of international relations, and cannot be considered as neutral with respect to their impacts on the natural environment.