Lateral Pressure refers to any tendency (or propensity) of individuals, societies, and states to expand activities and exert influence and control beyond their established boundaries, whether for economic, political, military, scientific, religious, or other purposes. Lateral Pressure theory seeks to explain the relationships between characteristic features of states and patterns of international behavior. The theory addresses the sources and consequences of such a tendency.

What follows is a brief introduction to the development of lateral pressure theory. The focus is elements of theory. The research that supports the theory – conceptual and empirical – is reviewed in another segment of this website. By separating matters of theory from those of research, we seek to be as transparent as possible and, if necessary,  possible, to retrace and highlight the investigations—both general and specific.

Logic of Lateral Pressure—Causal Logic

The causal logic runs from the internal drivers – population, resources, technology – the master variables whose interactions define the profiles of states and, through intervening processes, shape their external behavior. State profiles are defined by the relative salience of the individual master variables (measured empirically). (Choucri and North 1989). Central to lateral pressure theory is the defining proposition of differential rates of change. The complexity lies in the fact that the proposition coversing proposition of differential rates of change. The complexity lies in the fact that the proposition covers:

1. differentials among the master variables (population, resources, and technology) within countries,
2. differentials among the master variables between countries, and
3. differentials among master variables and differentials across countries.

As states expand their activities outside territorial boundaries, they encounter other states similarly engaged. Expansion may result in intersections among spheres of influence and set in motion complex interactions that can lead to escalation and conflict – or to cooperation and collaboration – depending on intents and capabilities.

The intersection among spheres of influence is the first step in complex dynamics leading hostilities, escalation, and eventually, to conflict and violence. These processes are contingent on the actors’ intents, capabilities, and activities.

Simplified causal logic of lateral pressure theory. Source: Choucri and Agarwal (2017).

Drawing on insights and evidence from the social sciences (as well as natural sciences and, more recently, engineering), lateral pressure theory can be understood in terms of its basic assumptions, its components, and their interconnections.

Assumptions

Lateral pressure theory assumes that each statistic is an indicator of—and consequence of—a discrete decision by an individual human being governed by his or her preferences. The larger the size of the community, the greater the demands, wants, and needs. Population growth, for example, is in fact the outcome of a large number of discrete private decisions (due to volition or to coercion) over which policy makers or national governments are not likely to have direct control.

In this connection, if there is any “determinism” in this logic, it is one driven by individual decision. Indicators of technology, like those of population, are also the observed outcomes of a number of widely dispersed decisions by individual actors such as developers, inventors, scientists, investors, manufacturers, etc. The same holds for resource access and usage. Statistics involve descriptions of and generalizations about aggregates. Empirical analyses of lateral pressure theory have gone through several phases, with each phase providing grounds for added developments in theory and new challenges for quantitative analysis.

Phases of Theory

The development of lateral pressure evolved over six phases of inquiry, each with its own theoretical and methodological features and challenges. The first three concentrated on the traditional geospatial realm, the "real" world. The fourth and fifth phases focused on the effects of human activity on the natural environment and implications for sustainability—two then-novel features of international relations and world politics. The sixth and most recent phase focuses on the construction of cyberspace—with its new data challenges, measures of master variables, analysis of state profiles, and propensity for expansion.

Properties of Theory

The essence of Lateral Pressure theory can be summed in twelve core properties. The quantitative analysis of the "real" world – defining actors, entities, systems of interactions, and forms of behavior – is illustrates departures from conventional theory in international relations.

Theory - Natural Environment

By now everyone recognizes the impacts of human activity on the natural environment and the very clear threats to life supporting properties. If there are contentions, these are mainly on matters of intensity rather than on the salience of the natural environment or on the fundamentals of environmental degradation.

Theory - Cyberspace

Lateral pressure theory views cyberspace as a global domain of human interaction. This domain is:

• Created by the interconnections of billions of computers within a global network—today the Internet and all of its derivatives; 
• Built as a layered construct where physical elements enable a logical framework of interconnection; 
• Empowered by the processing, manipulation, exploitation, augmentation of information, and interaction of people and information; 
• Enabled by institutional intermediation and organization; and
• Characterized by decentralization and interplay among actors, constituencies, and interests. 

This new “space” of interaction is a source of vulnerability, a potential threat to national security, and a disturber of the familiar international order. It has already created major changes to structures and processes of international relations. To date, we have addressed select critical imperatives—namely, challenges to the state, new security dilemmas, states defined in terms of cyber vs. real profiles, and modes of lateral pressure in "real" vs. cyber domains.

Until recently, cyberspace was considered largely a matter of low politics—the term used to denote background conditions and routine decisions and processes. By contrast, high politics is about national security, core institutions, and decision systems that are critical to the state, its interests, and its underlying values. Nationalism, political participation, political contention, conflict, violence and war are among the most off-cited aspects of high politics. But low politics do not always remain as such.

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