Date of Award

Spring 4-1-2021

Document Type


Degree Name

Doctor of Philosophy (PhD)


Political Science

First Advisor

Monteiro, Nuno


Why do great powers adopt expansionist foreign policies? Despite its great variety, much of the existing literature shares a common characteristic: that of seeing expansion as the centrally-driven and strategic extension of the state’s territorial domain. However, many important historical instances of great power expansion do not comport with these expectations, showing expansion to be far more peripherally driven and far less strategic than they would expect. In this dissertation, I make a distinction between centrally-driven “strategic expansion” and peripherally-driven “inadvertent expansion,” and I explain inadvertent expansion in the modern history of great power politics. I make three central arguments. First, inadvertent expansion is a surprisingly general phenomenon, occurring in approximately one-in-four cases of great power territorial expansion. Second, inadvertent expansion is a manifestation of a principal-agent problem, being much more likely to occur when leaders in the capital have limited control over their agents on the periphery of the state or empire. Third, leaders will be more likely to engage in inadvertent expansion when the perceived geopolitical risks associated with doing so are relatively low. These arguments are supported with a mixed-methods research strategy. First, I present and analyze new quantitative data on great power territorial expansion, comprising 250 observations coded as either strategic or inadvertent from 1816 to 2014. Second, I lay out a series of paired qualitative case studies of great power inadvertent expansion (and non-expansion), including an introductory case of the United Kingdom in Sind (1843); the United States in Florida (1818-19) and Texas (1836-37); Russia in the Khanate of Kokand (1864-66) and the Ili Region (1871-81); France in Tonkin (1873-74, 1882-83); Japan in Manchuria (1931-32) and Italy in Fiume (1919-20); and Germany in East Africa (1885) and Kenya and Uganda (1890). The arguments and evidence in this dissertation have important implications for the literature on territorial expansion and international relations theory more broadly.