Chapter 5 addresses the puzzle of reversing state size, which is inconsistent with a Tillyan account of European history. We argue that border-change processes triggered by ethnic nationalism are the main drivers of this development. While unification nationalism increased states’ size in the nineteenth century, its effects were dominated by secessionism, which shrinks states. Irredentism, in turn, had no effect on average state size. Focusing on deviations from the nation-state ideal, we postulate that internal ethnic fragmentation leads to secession and reductions in state sizes and that the cross-border presence of dominant ethnic groups makes state expansion through unification or irredentism more likely. Conducted at the systemic and state levels in Europe and globally, our analysis exploits information at the interstate dyadic level to capture these border-change processes. We find that while nationalism exerts both integrating and disintegrating effects on states’ territories, it is the latter effect that has dominated since the twentieth century.

Fourier methods for the analysis are developed and used for the analysis of the kernel of Green’s operators, the causal fundamental solution and the kernel of the fermionic projector.

The Hadamard expansion of the kernel of the fermionic projector is derived. The connection to the light-cone expansion and the wave front set is worked out.

Adding temporal depth, Chapter 8 evaluates the influence of past golden ages on nationalist claims and conflict. It extends Chapter 7’s analysis of the nexus between nationalism and conflict by adding temporal depth and assessing whether restorative nationalism increases the risk of conflict. Taking nationalist narratives seriously, we study how the wish to restore past golden ages can be used to legitimize territorial claims and mobilize resources for action, as it did for the Polish nationalists who repeatedly rebelled against Russian occupation throughout the nineteenth century. The goal is to reconstruct plausible golden ages by combining ethnic settlement data with information on European state borders going back to 1100 CE. The analysis shows that the availability of a plausible golden age during which a group enjoyed political independence increases the risk of both domestic and interstate conflict. These findings suggest that specific historical legacies make some modern nationalisms more consequential than others, an interpretation that challenges radically modernist takes on nationalist mobilization.

Chapter 2 introduces the main theoretical framework as well as the core concepts supporting the empirical analyses. It starts by outlining our response to the four weaknesses of the nationalism literature, followed by a depiction of the causal scheme that constitutes the analytical core of the book. The chapter also discusses key causal mechanisms supporting this framework before turning to alternative explanations and extensions to the scheme.

Evolutionary theory and especially evolutionary psychology have been recruited to explain and justify women’s constrained social roles and the restrictions historically placed upon them in mass societies. This chapter, on scientific grounds, challenges three myths allegedly emerging from empirical research: the myth of female intellectual inferiority, the myth of female domesticity, and the myth of female natural monogamy. While there are anatomical, physiological, and psychological differences between men and women, reflecting their different reproductive strategies, the overuse of the principle of comparative advantage has resulted in the subjection and exploitation of women in nearly all known societies.

The Euler–Lagrange equations for causal variational principles are derived, and their general structure is discussed.

This chapter reflects on how international organizations may affect the legal position of non-members – and the international legal system more generally – by imposing or exporting norms. It considers the aspiration latent in universal international organizations to bend the outside world to their will, looking at examples from the practice of the UN Security Council and the International Criminal Court. It then turns to the practice of the OECD and the EU to examine some of the ways in which regional international organizations may export norms to non-members through international cooperation and unilateral action, and some of the normative concerns that this form of engagement raises.

A functional analytic method is developed, which gives rise to a canonical decomposition of the Dirac solution space into two subspaces, even in a time-dependent situation.