Chapter 7 traces how interwar fears of entanglement and executive adventurism reshaped constitutional war powers – and how World War II then blurred the line between neutrality and war. It begins with Congress’s effort to constitutionalize restraint: proposals like the Ludlow Amendment and, more durably, the Neutrality Acts, which used trade, finance, and foreign commerce powers to reduce the risk of sliding into conflict. The chapter then examines the era of “almost-war” from 1939 to 1941, when Roosevelt and Congress invoked emergency authorities and defense measures while the nation remained formally at peace. In this era, war-powers authority expanded gradually rather than at a single moment, leaving unclear when and how constitutional checks were meant to engage. Once war came, total mobilization deepened World War I precedents, but the constitutional “switch” from peace to war mattered less after the New Deal expanded baseline federal power. The chapter also confronts the civil-liberties costs of judicial deference, most starkly Japanese–American internment, before turning to the postwar constitutional challenge of reconciling the UN’s collective-security commitments with a war-powers system designed for autonomy and non-entanglement.

Chapter 4 explores how diplomacy was practiced during the Cold War, focusing on how the period reshaped diplomacy and international law. The chapter challenges the view of the Cold War as merely a diplomatic struggle, suggesting instead that it was a struggle over the nature of diplomacy itself. It examines three key struggles: the relationship between openness and secrecy, diplomacy as performance and the concept of neutrality. The Cold War saw a return to secret diplomacy – public diplomacy was intertwined with intelligence and covert operations. In contrast, anti-colonial diplomacy emphasised openness and solidarity, using international institutions as platforms for lawful encounters. The chapter also discusses the contest over neutrality, with European international law protecting neutrality, while the Amero-Soviets disparaged it. The Non-Aligned Movement embraced active neutralism, rejecting Cold War bipolarity. The chapter highlights the diplomatic style of the Third World, which sought to assert a different international law and world order. It critiques the Western response, characterised by anti-diplomacy, relegation, and interventionism. The chapter concludes by emphasising the importance of recognising the plurality of diplomatic practices and international laws during the Cold War, and the ongoing struggle to reconfigure global politics and law after empire.

This chapter examines how state neutrality can be assessed by reference to the provision of certain information, with a particular focus on information provided through prenatal testing programmes. The information that parents receive about prenatal tests and procedures, and about disability, can be powerfully influential, and can shape the choices that are made. The chapter reviews a number of reasons why the provision of information might not reflect a neutral position: the information might be overly negative about disability, for example, and there is a risk that women will be blamed for any choice that they make. Although it must be acknowledged that it is not possible to have an entirely neutral framework, the chapter compares and evaluates different options that are thought to support autonomy. The chapter also considers nudge theory in order to critically assess both the state’s intention and some limits to individual choice. Although many of these limits are ones that the state cannot entirely avoid, it is important to consider how they put the parents in a particularly vulnerable position, where there is a risk of manipulation.

This chapter examines some further difficulties in interpreting the meaning of state neutrality in the context of prenatal selection practices, and that are tied to the state’s approach to disability. A first set of difficulties relates to the challenging or impossible task of identifying a value-neutral definition or concept of disability. If such a definition cannot be found, it is certainly hard to see how the liberal and neutral state can act, although a review of liberal commitments can indicate that certain approaches are more neutral than others. A second set of difficulties is associated with the fact that many parents of disabled children feel that some of their most important values change after their child is born, though they could not have anticipated or understood this change in advance. This common experience, which could be a type of transformative experience, suggests that prospective parents might not be able to make an entirely rational and informed choice, and that the state’s supposed support for autonomy might need some qualification.

Although Argentina maintained a neutral stance throughout the Great War and most of the Second World War, the country actively engaged in a humanitarian mobilization facing both conflicts. The significant influence of European immigration and the dynamic cultural and economic connections with the Old Continent played a pivotal role in this regard. This chapter examines the evolution of the government and civil society’s involvement in humanitarian initiatives throughout the period, emphasizing the continuities and shifts.

This conclusion reflects on the importance of studying the two world wars as moments of interconnectedness, when societies, economies, and cultures interacted with one another across national boundaries. It insists on the importance of moving beyond solely diplomatic, military, and political histories to instead prioritize transnational and transimperial perspectives, acknowledging groups and individuals above and below the level of states. Several categories are particularly useful in this endeavor: home fronts, colonial mobilization, captivity, occupations, and neutrality. Taking stock of these helps to highlight new frameworks of experience spread across the world. Finally, there is the important question of the relationship between the world wars and globalization. By their nature and by the reactions they prompted, these two global conflicts were ultimately the agents as much as the opponents of that process.

This chapter concludes the book by revisiting its key findings and by reflecting on their meaning from a broader perspective. The first half of the chapter consists of a summary of the rise and fall of the classical doctrine of civil war as explained in the preceding chapters. The second half assesses the overall legacy of the classical doctrine in the light of modern legal theory, and observes how the classical law was hardly better able to overcome the problems of indeterminacy and recognition than current principles are. Yet this does not mean that the classical doctrine would have been meaningless, as its practical utility may have been based precisely on its limited effectiveness and inevitable ambiguity.

This chapter explores the golden era of the classical doctrine of civil war, which lasted until the middle of the nineteenth century. Its focus is on the Spanish American revolutions and the emergence of the law of neutrality in the context of civil wars. The several case examples illustrate how the familiar questions and disputes from the previous chapters persisted and developed in state practice throughout the period. In addition to the Spanish American revolutions, the chapter also discusses the impact of European and American revolutionary ideologies on international movements and illustrates the significant practical limitations of the classical doctrine: while it stemmed from the practice of the transatlantic world, elsewhere in the world it often seemed absent or selectively applied to deny the legal standing of indigenous and colonial insurgents, or to legitimise local rebellions within Oriental empires.

The decline of the classical doctrine of civil war in state practice began right after the American Civil War, when the concept of belligerent recognition had barely been coined in the legal literature. There were several reasons for this. First, after the abolition of privateers in the 1856 Declaration of Paris, the maritime powers had essentially deprived future insurgents of their primary weapon at sea, the privateer. Second, developments in the law of neutrality after the Geneva arbitration raised the prospect of state responsibility towards belligerents for neutral states. Third, as indeterminate pragmatism became a diplomatic norm, new legal vocabularies began to develop that were seemingly independent of questions of formal recognition. New, deliberately ambiguous approaches to recognition emerged, especially in the Latin American insurgencies, such as the recognition of insurgency doctrine.

In this chapter, early efforts at legal codification relevant to submarines are seen in the work of learned societies, such as the Institut de Droit International and the International Law Association, as well as in discussions leading to the conventions adopted at the two Hague Peace Conferences. However, submarines were not specifically addressed but fell within a category of belligerent warships; an early proposal to ban submarines as weapons being unsuccessful. Discussions at this time concerned passage in territorial waters and straits, and particularly the rights and duties of belligerents and neutrals. International law on navigational rights in territorial waters was unsettled as World War I began. The critical role of submarines during World War I prompted States to adopt laws that specifically addressed submarines, including requirements to surface in the territorial sea. The chapter reflects on these emergent laws regulating submarines in both times of war and peace.

This chapter examines legal developments in submarine regulation taking into account the political context existing prior to World War II, including tensions in the Pacific with Japan’s aggression against China. Notably, States adopted the 1936 London Protocol on Submarine Warfare seeking to align requirements for submarines with obligations imposed on surface warships. Tensions in the 1930s also prompted Turkey to initiate a revision of the legal regime governing the Turkish Straits, leading to the Montreux Convention and the near complete prohibition of submarine passage in these waters. With the outbreak of World War II and unrestricted submarine warfare, questions emerged as to the viability of rules set out in the 1936 London Protocol. States also moved to revise laws of neutrality with more targeted consideration of submarines. The chapter thus reflects ongoing legal developments concerning navigational rights of submarines in territorial waters and the regulation of submarines during armed conflict.

In assessing international law governing submarine warfare, we consider how peacetime rules from the law of the sea apply in an armed conflict and focus on the law of neutrality and the law of armed conflict (international humanitarian law). The allocation of rights and duties within different maritime zones continues, albeit with some modifications, during an armed conflict. Most notably, the law of neutrality establishes how those rights and duties change depending on a State’s status as a belligerent or neutral. The use of submarines during armed conflict is also governed by the law of naval warfare and they are largely subject to the same rules that restrict surface warships in relation to targeting, as well as the means and methods of warfare. While submarines are predominantly governed as warships, we note how operational limitations of submarines may affect the interpretation of some rules.

The Second World War posed an existential crisis for the League of Red Cross Societies. This chapter explores how the League attempted to fulfill its primary task of coordinating the work of National Societies when the movement was at war with itself, and when the Red Cross principles were flouted by the belligerent militaries and ignored by their National Societies. By focusing on the League, rather than the ICRC, the chapter broadens our understanding of the Red Cross movement during the conflict. The war illuminated some of the strengths as a network but also exposed some of its latent weaknesses. The chapter shows how, far from being a hiatus in the League’s history, the war years were critical in shaping the wider development of Red Cross humanitarianism. They accentuated the importance of American leadership for the League but also accelerated thinking over the League’s involvement in international relief efforts and sharpened its ambitions to leadership over matters relating to civilian populations in times of war. Both these factors were vital to the way the League legitimised its place within the Red Cross movement and the trans-Atlantic approach taken to articulating the role of the Red Cross in the post-war world.

The servants in Elizabeth Bowen’s fiction, increasingly complex, allow her to represent, variously, Irishness (Donovan and his daughters in The Heat of the Day), the paid companion’s difficulties in living intimately with an employer (in several short stories), a housekeeper who maintains family memories with its furniture (Matchett in The Death of the Heart), and even a murderer who resents his position as a flunkey (Prothero in ‘The Disinherited’). These portrayals allow explorations of class loyalties, predicaments, and resentments, as well as subtleties of Irishness and Irish neutrality during the Second World War. This chapter examines paid companions, Irish help and their informal relationships with their employers, and morally forceful servants who contribute to the advancement of plot. Bowen’s servants often prompt their employers’ confrontation with the reality of their moral, social, or historical circumstances; by doing so, they can expose or puncture their employers’ illusions about their respective worlds.

This chapter examines the foundations of Sarah Wambaugh’s political thought and attempts to reconstruct her world view. Wambaugh’s avid support for the League of Nations was premised on her understanding of it as a new scientific way of conducting international politics. Key to her faith in political science, and later forming a key part of her prescriptions for the plebiscite, was her belief in the importance of neutrality, a concept of international law then in flux. Alongside neutrality, the concept of public opinion was also in flux, with debates as to its relationship to democracy and expertise. The chapter points to the way in which public opinion and perceptions were also integral to her later normative prescriptions for the plebiscite, and ends with an examination of Wambaugh’s own public relations campaign for American entry to into the League of Nations.