perhaps walker's largest body of work is on the topic of state sovereignty. because modern theories of international relations were created in a time when state sovereignty was a given cornerstone of political theorizing, modernist theorists continue this trend, despite it becoming increasingly less apparent. though walker denies cosmopolitanism and the assumption that state sovereignty will eventually be a thing of the past, he stresses the importance of modern theorists to acknowledge the decline of a states ability to act autonomously within its own fixed borders. the european union is an excellent example of states that are slowly losing sovereignty in a way many traditional ir theorists fail to realize.