In its jurisprudence, the ICJ has developed a hierarchy of sources it will rely on to resolve territorial disputes: it prioritizes a boundary treaty between the state litigants, followed by agreements between the states’ colonial predecessors, and finally state litigants’ actions displaying their authority over the disputed territory. The Court’s practice therefore leaves no room for local populations to contribute to boundary-making decisions. Given the status self-determination holds in international law today, and the repercussions possibly faced by such populations in certain territorial disputes, there is cause to consider that the desires of local populations should be considered in the Court’s legal reasoning. This article first unpacks the reasons that self-determination is not brought up by state litigants on one hand, nor by the Court on the other hand. It notes that self-determination is only rhetorically addressed by states if buttressing their interests. It therefore attempts to reconcile self-determination with territorial disputes, suggesting how peoples’ desires may be factored into the Court’s approach.

Under pressure to choose between the U.S. and China, Southeast Asian countries have adopted a hedging strategy: deepening economic relations with China while strengthening security cooperation with the U.S. How does the region's public view this strategy? With tensions rising in South China Sea territorial disputes, are more nationalistic individuals more likely to oppose hedging? Using an original public opinion survey conducted in the Philippines, we find that while an overwhelming majority of respondents were concerned about the territorial disputes, more nationalistic Filipinos were no more concerned than less nationalistic ones. Further, more nationalistic Filipinos were more likely to view economic relations with China as important for the Philippines and to approve of Duterte's China policy, which follows the logic of hedging. These surprising findings suggest that under the shadow of great-power competition, the link between domestic politics and foreign policy is nuanced in the Philippines, and Southeast Asia in general.

This article analyses the growing resistance to judgments of the International Court of Justice arising out of domestic law in Latin America, through a study of challenges to the authority of the Court’s judgments regarding territorial and maritime delimitation in the region. These challenges are based upon the ‘territory clauses’ found in many Latin American constitutions, which were used to set national boundaries following colonial independence. Territory clauses that once developed international law doctrines such as uti possidetis iuris are now being used against prevailing international law rules, in a process described in this article as ‘constitutional resistance’.

This article explains the nature of ‘territory clauses’ in Latin America, i.e., clauses that constitutionally define the national territory in reference to international law. It then describes the process of ‘constitutional resistance’, by which local authorities have used these clauses to oppose ICJ judgments, leading to various results, such as non-appearance in further proceedings, constitutionalizing exclusively favourable judgments, deferring the implementation of a judgment to the Constitutional Court or implementing only certain ICJ judgments, while creating legal barriers to the implementation of judgments that, in the State’s view, negatively affect their territory.

These challenges based on territory clauses are studied through prominent ICJ cases involving Nicaragua, Honduras, El Salvador, and Colombia. The article also explores how the lack of a strong territory clause eased the implementation of the Peru v. Chile judgment, and how the recent non-appearance of Venezuela in its current ICJ proceedings with Guyana, is partly based on constitutional justifications.

The Judgment of the Court of Justice of the European Union (CJEU) in Slovenia v. Croatia marks the anticlimax of a long-running territorial dispute. It is also only the sixth time the CJEU has issued a judgment in a case instituted by one European Union member against another. Among these cases, it is the first to consider an arbitral award in a dispute between members, the first to consider a boundary dispute between members, and the first to be dismissed for lack of jurisdiction. The Court found that it cannot rule on alleged infringements of European Union law when these arise from the breach of a treaty falling outside of the Union's subject-matter competence. Most directly, the Judgment may pose significant consequences for European Union internal affairs in the near term, such as Croatia's ambitions to join the Schengen Area and the Eurozone. More broadly, several of the Court's findings will be relevant beyond the European legal order, particular those concerning the meaning and effect of “ancillary” legal questions, and the bilateral or multilateral character of a dispute involving admission to an international organization.

Past studies conclude that a territorial integrity norm caused territorial conquest to decline sharply after 1945, virtually subsiding after 1975. However, using new and more comprehensive data on territorial conquest attempts, this study presents a revised history of conquest after 1945. Unlike attempts to conquer entire states, attempts to conquer parts of states remained far more common than previously recognized. More than conquest declined in frequency, its relationship with war evolved. Challengers attempting conquest before 1945 often initiated a war, then sought to occupy large territories. Today, challengers more often seize small regions, then attempt to avoid war. Adopting this strategy, the fait accompli, challengers increasingly came to target territories with characteristics that reduce the risk of provoking war—such as a low population and the absence of a defending military garrison—but challengers nonetheless take a calculated gamble. In part because seizures of smaller territories with such characteristics have not declined, the operative constraint appears to be against war-prone aggression, not territorial revision. The evolution of conquest is a symptom of war's decline, not its cause. Most of the evidence that the territorial integrity norm suppressed conquest or war withers under investigation with new data. Attempts to get away with seizing small pieces of territory are likely to be a defining element of the twenty-first-century international security landscape.

Five decades after the wave of independence of the 1960s, have all African territories been decolonized in accordance with international law? On the basis of the General Assembly and state practice, this study argues that only the continuing possession of African territories by colonial powers is contrary to the obligation to decolonize under international law. Thus, colonialism is still persisting in Africa with regard to the Glorious Islands, Mayotte, the Chagos, Ceuta and Melilla, the islands Alhucemas, Chafarinas, Leïla, and Peñon de Vélez de la Gomera. These territories belong respectively to Madagascar, the Comoros Islands, Mauritius, and Morocco. However, the obligation to decolonize under international law, which is premised on the existence of a colonial possession, does not provide any legal basis to claims directed against independent African states. Besides, the maintenance of boundaries existing upon the achievement of African countries to independence is not a case of enduring colonialism.

The validity of historic or ancient title to territory has been tested in numerous international judicial proceedings, both in the International Court of Justice and in international arbitration. Historic title usually originates in ancient normative systems, including tributary, feudal, sultanate, and Islamic systems that predate the Western international legal system. Nevertheless, the rules against which historic title has been tested in international judicial proceedings generally require that the original titleholder be a state or a central authority that exercised territorial sovereignty over a defined space to the exclusion of other sovereign powers. The rules that apply specifically to these ancient normative systems, where allegiance to authority was personal or religious rather than territorial, have been seen as irrelevant compared to the more contemporary determinations of historic title. The only exceptions have been the French medieval customary norm frankalmoign, which the international arbitral tribunal in the Minquiers and Ecrehos case cited as evidence that the English king exercised territorial sovereignty over the disputed islands, and the personal allegiance of the Orang Laut to the Sultan of Johore, coupled with the recognition accorded to the latter by the great maritime powers, which the International Court of Justice in Malaysia v. Singapore found sufficient to prove the historic title of Malaysia over Pedra Branca/Pulau Batu Puteh and Middle Rocks. The principles by which historic title were adjudicated in these cases appear to be the same principles by which the Western powers dealt with the claims of the People's Republic of China and Vietnam to the Paracel Islands and the Spratly Islands, not only during the colonial period but also after the Second World War. This analysis suggests how the International Court of Justice or an international arbitral tribunal might, if given the opportunity, resolve these South China Sea disputes. Readers might also find this analysis to be particularly relevant to other disputes involving historic title, including the East China Sea disputes, although the focus of this article is on the South China Sea disputes. States and other commentators are left to rely on their own preferences and allegiances in reaching their own normative conclusions using the novel analysis provided by this article.