The two crises in this chapter share three main characteristics. They involve territorial (border) conflict that relates to the independence of Ukraine (or, relatedly, the breakup of the Soviet Union), feature an East–West tension, and (as of this writing) do not escalate to a war among the major states. In 2014, after Ukraine attempted to move closer to Europe (i.e., it contemplated an EU agreement and the pro-Russian government fell), Putin annexed Crimea to secure the long-held naval base there. Although done forcefully, there were no military fatalities. In 2022, amidst a fear that Ukraine was again moving closer to Europe (i.e., it looked to be closer to joining NATO and its government became less pro-Russian), Russia invaded Ukraine. It failed to take Kyiv, even though it heavily bombed Ukraine. Russia then withdrew to the east, where a majority of Russian speakers had sought to separate from Ukraine. The United States and the European Union gave weapons and aid that expanded as the war continued. Deaths mounted on both sides. The Russians successfully created a land bridge from the Donbas to Crimea. After his election, Trump attempted to negotiate a settlement that would end the war.

This chapter summarizes the main lessons for diplomacy that we derive from our study. These eight lessons are: 1. A major factor separates the crises that escalate to war from those that do not; in the latter, a strong leader reins in any hard-liners who advocate going to war. 2. Individuals make a difference. 3. Contingency plays a more important role than system structure in determining whether or not a crisis escalates to war. 4. Someone must stand for peace. 5. The secret to preventing war structurally is to find a functional equivalent to war. 6. Norms and rules are important for avoiding war – and, therefore, maintaining peace. 7. War can be avoided; it is not inevitable. 8. The realist concepts of the national interest and balance of power do not always accurately describe the behavior of states.

The Munich conference notoriously symbolizes appeasement and its failure. The issue under dispute concerns territory – specifically, the Sudetenland. This territorial dispute was initially internal to Czechoslovakia, a disagreement between the Sudetenland Germans and the central government of Czechoslovakia. Eventually, however, the nationalistic element to the dispute brought in the German government. The major powers avoided war because the French and British prime ministers – Daladier and Chamberlain, respectively – forced the Czechoslovakian president, Benes, to accept the peaceful transfer of the Sudetenland to Germany, based on the norm of nationalism (or self-determination). As this case shows, when actors widely agree on the norms through which territory can change hands, the probability of war declines. Nevertheless, this peace was short-lived. Indeed, the afterword to the chapter describes how Hitler invaded Prague shortly thereafter. The Danzig–Poland crises then followed. By that point, Britain and France had abandoned appeasement and shifted to balancing against Hitler; they allied with Poland and gave Hitler an ultimatum to try to stop his invasion. This conventional deterrence failed, and the Second World War began in Europe.

Italian unification ultimately emerges through four wars. This chapter covers the second of these wars (1859–1860). Austria holds sovereignty over territory in northern Italy. Cavour, the prime minister of Piedmont, learns from the first war (1848) that Piedmont cannot defeat Austria – and therefore wrest Italian lands from it – without a powerful ally. He secures an alliance with Napoleon III of France, and at a secret meeting in Plombières, Piedmont and France plot a war. The Italian nationalists argue that the “people” of a nation have a legitimate right to self-rule. The Concert plays no role in this crisis because it does not see the norm of nationalism as a legitimate justification for owning territory. In its view, the norm of dynastic succession (i.e., a king or queen coming to the throne) serves that purpose. The Concert system is therefore biased against the nationalists. The resulting clash of norms increases the probability of war. Nevertheless, territorial issues are generally more war-prone than non-territorial issues, and infusing territorial disagreements with nationalism and identity (or ethnic) claims raises the probability of war further. In the end, the case illustrates well why and how territorial issues lead to war.

Neither the First nor the Second Moroccan Crisis escalates to a war between the major states. In the First Moroccan Crisis, Kaiser Wilhelm II did not believe it was worth fighting a war over Morocco. In the Second Moroccan Crisis, the actors had recourse to the norm of compensation, which provided a focal point and procedure that guided the negotiations. It ultimately made a bargain possible and facilitated a peaceful resolution to the crisis. Nevertheless, despite the use of the norm of compensation and accommodationists at the highest levels of German decision-making, the case shows that coercive bargaining could have led to war.

Constructivism emphasizes the role of ideas, identities, and norms in shaping state behavior and international politics, as well as the intersubjective and relational nature of these ideational factors. Social relations “make or construct people – ourselves – into the kinds of beings that we are. Conversely, we make the world what it is, by doing what we do with each other and saying what we say to each other” (Onuf, 1998, 59). Constructivism therefore highlights the intangible yet relational aspects of our reality: a world in which the meaning of objects and actions is not fixed but socially constructed through our interactions; states are held together by collective belief and actively participate in the social construction of anarchy. Norms play a significant role by defining appropriate behavior and enabling action by providing a framework for actors to understand and interact with the world.

This chapter explores the dynamics of non-linear changes within social systems, focusing on the processes that lead to societal collapse and ‘emergence’ (when a new social order forms that is qualitatively different from the past). The chapter first reviews the forces that create stability, differentiation, and oscillation. The DIME model is introduced, which explores how activists choose tactics to follow up the success or failure of their collective action. The chapter explores dynamics of intergroup contestation, including polarisation and backlash that drive systems towards either emergence or collapse. System stability is supported through coordinated identities and norm sequences that are often localised spatially, which act as homeostatic mechanisms to create resilient systems. However, behavioural changes manifest as actors establishing new cues and framing collective actions in ways that channel energy towards new identities and norms. Finally, the chapter explores mutual radicalisation, where mutual feedback loops of failure and threat signals between groups drive radicalisation, reinforcing intergroup tensions.

This chapter introduces the dynamics of ecosystems and chaotic systems, providing an accessible overview for readers unfamiliar with complexity theory. Key concepts such as fractals and emergence are defined and applied to social groups through the FLINT model of Factional Leadership, Intergroup Conflict, Norms, and Time, which explains how factions and subgroups form and ferment within a seemingly unified group. This model examines forces driving subgroup differentiation and the challenges of achieving lasting social change because of the need to influence multiple groups simultaneously and overcome resistance. The chapter revisits psychological research on effective activism, underscoring the importance of addressing both conformity and dissent within and between groups. Finally, we discuss empirical methods for analysing these complex dynamics, including network analyses, person-centred analyses, and agent-based modelling, which offer new ways to understand and study the formation and evolution of groups.

The chapter begins by examining how groups form and socialise members, and the forces of conformity that sustain existing norms. We then consider the emergence of differentiation and innovation, exploring how processes of minority influence and dissent challenge conformity. The chapter then explores the impact of contested norms, particularly in systems of inequality, and considers how these norms are challenged and transformed under more repressive and open regimes. This chapter also explores power, repression, agency and resistance, and how reinterpretations of classical studies by Milgram and Zimbardo are now understood through the lens of social identity theory. The transmission of norms between groups is discussed, alongside the entrepreneurs of identity who mobilise advantaged groups to support disadvantaged groups. This chapter makes a transition from traditional theories of intergroup relations to new paradigms that emphasise the fluidity of norms, the role of emerging leadership, and the transformative potential of identity in group dynamics.

As coal burning was explicitly politicized with reference to coal’s contributions to climate change over the last ten to fifteen years, a number of policy norms associated with phasing out coal burning (or its financing) have emerged and stabilized in transnational politics. This chapter tracks aspects of these normative politics focusing on both the promulgation and diffusion of the new policy norms and a number of critiques and challenges – many grounded in distributional and procedural justice – to coal phaseout norms that emerge as a response to the transnational promulgation of coal phaseout policies.

Chapter 4 is the first of the three chapters that draw on interviews, observations, and life stories from Bosnia and Herzegovina to narrate a story about what ‘Never Again’ means for the people in this country and formulate a claim about transitional justice’s complicity in the construction of conflict recurrence anxieties. This chapter proposes that the lack of state-sponsored, state-wide truth recovery and a national dialogue about the characteristics, dynamics, and consequences of the war creates anxieties about potential conflict repetition. It then demonstrates how the global project of transitional justice is complicit in creating and sustaining these anxieties. In particular, the chapter shows how the normative hierarchy of transitional justice and the positioning of the International Criminal Tribunal for the former Yugoslavia as a key source of the historical status quo helped enhance the building of multiple, competing, and often parallel biographical narratives about the war that prolong anxieties about potential conflict recurrence.

The changes at play in the contemporary world bring about challenges that are impacting political legitimacy. They make legitimacy at the same time more problematic and more relevant, at both the national and international levels. From this perspective, how these changes and challenges are going to be addressed in the coming years is likely to determine, to a large extent, the evolution of political legitimacy—nationally and internationally. Among the changes and challenges underway, and their associated events and trends, I highlight the following eight: (1) the challenge of integration and disintegration, (2) the economic and financial challenge, (3) the geopolitical challenge, (4) the normative challenge, (5) the technological challenge, (6) the reassessment of globalization challenge, (7) the crisis of democracy challenge, and (8) the governance challenge. I unpack them in turn and, for each of them, allude to their possible meaning and implications for political legitimacy.

Based on the degree of trust established in infancy, the belief in the possibility of control from the toddler period, and the successfulness of practice in peer interactions in the preschool, most children are prepared for the new meanings made possible by close friendships and real world competence of the elementary years. At times, success here can alter somewhat negative meanings brought forward from earlier eras. All children are now armed with logic and a more realistic understanding of causality. This allows them to see things as they are, including comparisons between them and others. A great leap in moral development occurs as children come to understand and affirm the value of rules and norms. Despite limitations in their degree of flexibility, embracing these norms can provide solid ground for the more relativistic and principled understanding of adolescence.