Together, five European states control thirty Overseas Countries and Territories (OCTs), which span the globe from the Arctic to the Antarctic via the Atlantic, Indian, and Pacific Oceans and the Mediterranean Sea. They vary widely in size, population, resources, and global relevance. In a time of political, economic, and military turmoil, this article takes stock of these OCTs to document who’s who and assess their respective importance on the world stage.

Europe’s thirty OCTs are linked to their parent countries either as remnants of defunct empires—in the cases of France, the Netherlands, and the UK—or by virtue of pioneering polar expeditions toward the North and South Poles—in the cases of Denmark, France, Norway, and the UK. Some entities are distant witnesses of past times, but several retain a distinct relevance in today’s world, such as the British Sovereign Base Areas of Akrotiri and Dhekelia, the British Indian Ocean Territory, Gibraltar, Greenland, New Caledonia, and the two French territories of French Polynesia and Wallis and Futuna in the South Pacific.

The wide disparity in available economic data does not allow for a rigorous ranking of the thirty countries and territories. This analysis therefore draws on a combination of published data and recent developments. The article divides the thirty entities into three broad groups before focusing on seven OCTs of strategic importance to Europe in the current geopolitical environment.

Who’s Who Among Europe’s OCTs?

Europe’s thirty OCTs can be classified into the following three groups:

• Group A: Anguilla; Aruba; Bermuda; Bonaire; the British Virgin Islands; the Cayman Islands; Curaçao; the Falkland Islands; Montserrat; the Pitcairn Islands; Saba; Saint Barthélemy; Saint Helena, Ascension, and Tristan da Cunha; Saint Pierre and Miquelon; Sint Eustatius; Sint Marteen; and the Turks and Caicos Islands.
• Group B: Bouvet Island; the British Antarctic Territory; the French Southern and Antarctic Lands; Peter I Island; Queen Maud Land; and South Georgia and the South Sandwich Islands.
• Group C: Akrotiri and Dhekelia; the British Indian Ocean Territory; French Polynesia; Gibraltar; Greenland; New Caledonia; and Wallis and Futuna.

This classification is by nature imperfect and fluid, especially as demands for critical mineral resources increase with technological advances. Remote territories may also be of strategic interest to non-European powers that aim at extending their reach to far-flung lands.

Group A: Seventeen Flag Bearers

The largest group of OCTs is composed of seventeen small islands or groups of islands in the Atlantic, Indian, and Pacific Oceans with particular political relevance as outposts of France, the Netherlands, Norway, and the UK around the world (see figure 1). Their main value is to fly the flag of their parent state in distant places and mostly empty oceans. In doing so, they primarily illustrate their home country’s past global presence.

However, this history is not these territories’ only relevance in today’s world, since new factors have emerged: demands for maritime resources and minerals, tourism, illicit trafficking, and control of shipping routes. For example, entities in this group often have very large exclusive economic zones (EEZs) that comprise sizable fish stocks and, in some cases, seabed mineral resources. These territories can also serve as staging posts for maritime patrols with several purposes, including fighting drug trafficking and controlling fishing permits.

In addition, many of these lands, including the most remote ones, have become valuable tourism assets, which, over time, may prove to be an environmental concern for some of them. Meanwhile, Chinese and U.S. diplomatic, military, and economic activities in the Pacific and Indian Oceans are triggering close monitoring by the parent states of the various OCTs.

Group B: Six Environmental Monitors

The second group is made up of six Arctic and Antarctic territories attached to France, Norway, and the UK as well as a series of remote islands linked to the UK in the South Atlantic and South Pacific Oceans and to France in the South Indian Ocean (see figure 2). Some of these entities are not permanently inhabited, home only to temporary groups of scientists and administrative staff. They have essentially scientific relevance, as they host teams that monitor the effects of climate change. In some cases, these territories also have important fishing areas. Although listed in group C below, Greenland is also relevant for climate research.

Group C: Seven Strategic Bastions

A third, not very homogeneous group is composed of seven territories with high relevance in terms of strategic position, military presence, mineral and maritime resources, or a combination of these factors (see figure 3).

The British Indian Ocean Territory, also known as the Chagos Islands, was separated from Mauritius in 1965 to become fully administered by the British government. Meanwhile, a British-U.S. lease agreement covers the use and maintenance of the Diego Garcia air and naval base, an important asset in recent years during conflicts in the Middle East. In 2022, the UK initiated a process of returning the Chagos Islands to Mauritius—which itself gained its independence from the UK in 1968—and an agreement was reached in May 2025. This treaty included measures to keep Diego Garcia under British control, to the benefit of the national security of the UK and its allies.

Initially, the U.S. government strongly supported the agreement: “We commend both the United Kingdom and Mauritius for their leadership, vision, and commitment to ensure that Diego Garcia remains fully operational,” said a U.S. State Department press release in March 2025.

However, in 2026, the United States challenged this process, although the operational character of Diego Garcia was never in question. This debate was complicated by Iran’s attempt to reach the archipelago with an intercontinental missile in late March 2026. At the time of writing, the divergences between London and Washington remain unresolved, while the British parliament’s approval of the return agreement has been suspended since April 2026.

Akrotiri and Dhekelia, located on the territory of the Republic of Cyprus, are governed by the UK under British law in full coordination with the Cypriot government. They host an important air base in Akrotiri, managed by the Royal Air Force, and the Dhekelia Station. The facilities were in the news in early 2026 in the context of the U.S. and Israeli military operations against Iran and the retaliatory strikes by Iran or its proxies: A drone hit Akrotiri on March 1, and two others were intercepted on March 2. These incidents have not disrupted the sites’ operations in any major way. However, recent research has underlined the destabilizing effect for Cyprus of the war on Iran.

Gibraltar, a strategically located port at the only natural entry point to the Mediterranean Sea, hosts a Royal Navy station. The territory’s relationship with Spain has disrupted relations between London and Madrid in the past, but in January 2026, the EU and Gibraltar struck an agreement to remove “all physical barriers on persons and goods circulating between Spain and Gibraltar, while fully safeguarding [the] Schengen [passport-free travel area], the EU’s Single Market, and its Customs Union.” The agreement was formally signed on July 14 in Brussels.

Greenland is best known for two reasons: It is the largest overseas land linked to an EU member country, Denmark; and it has been targeted by President Donald Trump’s claims that the United States should own the territory. Greenland hosts the U.S. Pituffik military base, established by a Danish-American agreement back in 1951.

After a controversial visit by U.S. Vice President JD Vance in March 2025, Trump made repeated claims that the United States needed to “own” or “get” Greenland for security reasons. These claims triggered major alarm on the territory, in Denmark, and in the EU.

On January 6, 2026, seven European countries clarified their positions on Arctic security issues and on the sovereignty of Denmark and Greenland. What matters here is the EU’s political stance, which was set out twice. First came a statement on January 14 by all the political groups in the European Parliament. Second, an informal meeting of EU leaders on January 22 said in essence that since Greenland is linked to Denmark and Denmark is part of the EU, the principles of international law, territorial integrity, and national sovereignty are not up for discussion.

During the NATO summit in Ankara on July 7–8, 2026, Trump renewed his claim that the United States should take control of Greenland for (undocumented) military reasons, while Danish Prime Minister Mette Frederiksen renewed her opposition to the claim.

U.S. threats have triggered a legal debate on whether or not the EU’s mutual-assistance clause applies to Greenland, given its status as an OCT of Denmark. Despite intensive work by specialists, there is no final position on this legal argument.

Beyond the heated debate initiated by the United States over Greenland’s strategic importance in military terms, there are two other domains in which the territory plays an important role.

One is scientific, because Greenland’s ice sheet, which covers 80 percent of the territory, is the second-largest glacier on earth—accounting for 8 percent of the world’s ice, against 91 percent for Antarctica—and represents a relatively easily reachable area for climate research.

The other domain is economic, since it is estimated that the ground below the ice sheet holds major reserves of strategic minerals. According to the Geological Survey of Denmark and Greenland, the island contains twenty-five of the thirty-four minerals classified by the European Commission as “critical,” including vast deposits of rare-earth elements, graphite, and lithium. Australian, Chinese, and U.S. mining companies hold permits granted by Greenland’s authorities, but the physical conditions—the climate, the depth of the ice sheet, and the absence of roads—and the legal framework for mining make these operations a challenging enterprise.

Greenland benefits from 45 percent of the EU’s 2021–2027 financial program for the OCTs. The program’s priorities are education, renewable energy, digital connectivity, critical raw materials, sustainable tourism, and environmental protection and research.

New Caledonia is a different case, as it has not been formally threatened by any foreign power. It is the largest inhabited OCT linked to France, and its legal status has been debated between the French government and local political forces that advocate independence. Several referendums have taken place, leading to the archipelago’s 2025 adoption of a modernized legal status, which provided a higher degree of self-administration.

New Caledonia possesses the world’s third-largest proven deposit of nickel ore, after Indonesia and the Philippines, making it a strategic territory. Despite high production costs, maintaining the mining and processing of New Caledonia’s nickel resources is a strategic objective of the French government. More generally, French researchers continue to monitor China’s economic and military presence in the Pacific Ocean.

Two other French OCTs in the South Pacific—French Polynesia and Wallis and Futuna—rank among the territories of high strategic importance by virtue of their large EEZs, which give them and France sovereign rights over a vast portion of the ocean, with consequences for fishing rights, tourism revenue, military control, and future mining rights. This situation creates a substantial burden of sovereign expenses for France in the form of administrative apparatus and land, naval, and air presence.

Non-OCT Strategic Entities

For the sake of completeness, it is worth mentioning three territories not listed as OCTs because they are integral parts of their home countries—Svalbard and Jan Mayen (Norway), French Guyana (France), and Ceuta and Melilla (Spain)—a legal status that protects them from foreign interference. These entities are nevertheless of high relevance in the current context of sharp competition for global presence.

Svalbard’s relevance is linked to growing interest in year-round shipping lanes in the Arctic; the archipelago also hosts a Russian mining operation. Jan Mayen, which is not permanently inhabited, is an observation post close to Greenland. Both are administered by Norway’s Polar Affairs Department.

French Guyana plays a major role in France’s and Europe’s space activities, which are coordinated by the European Space Agency. In addition, the anti-European posture of the 2025 U.S. National Security Strategy may result in new trade difficulties in the Caribbean, where France has several other overseas departments and regions in addition to French Guyana.

The Spanish territories of Ceuta and Melilla, located on Morocco’s Mediterranean coast, are integral parts of Spain but have become flash points during recurrent episodes of attempted migration from Moroccan territory. In addition, Ceuta, by virtue of its geographic position in the Strait of Gibraltar, has uninterrupted control of the territorial waters from the southern Spanish coast to its own coastline, making all maritime traffic entering or exiting the Mediterranean Sea navigate through Spanish territorial waters.

The Geopolitical Importance of Europe’s OCTs

As noted, Europe’s thirty OCTs reflect their parent states’ defunct empires or hardy explorations of faraway lands. Those parent countries consider their territories sufficiently important to allocate to them resources based on history, politics, or prestige. In addition, some of these thirty lands hold a substantial strategic, environmental, economic, or military interest.

In the case of the seven territories of strategic importance (group C), the geopolitical analysis is made more complex by today’s tense international context, which is characterized by three main factors. The first is the decline of the rules-based international order and the accompanying erosion of the regulating role of the UN. The second factor is the rising number of disruptive governments; these do not form a coherent club, but they certainly illustrate a trend. The third issue is the predatory behavior of some countries, based on imperial nostalgia, military interests, appetites for critical materials for new technologies, or massive financial resources.

This predatory behavior takes multiple forms, as observed in recent years. The most obvious example is Russia’s 2014 takeover of Crimea and Donbas in Ukraine, based on disputable arguments about historical links, the Russian language, and perceived threats from NATO countries. This case clearly falls outside the scope of this article.

Meanwhile, China has deployed a range of techniques in its overseas action, from a military presence, for example in the Arabian Sea during the 2026 U.S.-Israeli war on Iran or the creation of artificial islands in the South China Sea, to financial investments in strategic locations, such as the Port of Piraeus in Greece or France’s Toulouse airport, which hosts a major Airbus aircraft plant. These examples did not affect European OCTs, but they do reflect a pattern of behavior that could apply to many regions around the world, starting with increased trade and fishing and, in some cases, greater investment.

In the case of Trump, controversies often start with a statement on social media, as on Greenland: “Countries have to have ownership and you defend ownership, you don’t defend leases. And we’ll have to defend Greenland.” The notion of defending Greenland is associated with the military presence of China and Russia around the island. A long-term economic calculus, especially for critical raw materials, may also be at play. Trump used a similar style of communication this year about Diego Garcia, threatening to buy back the archipelago.

A Diplomatic Fait Accompli vs. Europe’s Democratic Architecture

These assertive moves reflect—in no particular order—financial power, military might, and territorial ambitions. They have no foundation in international law and go against the principles established in the years after World War II and, indeed, against the role attributed in the late 1940s to the UN system.

The actions of China, Russia, and the United States in recent months and years reflect different policies in specific contexts and are hardly comparable. But they have in common the creation of their own diplomatic fait accompli. By combining public and private financial means, economic strategy, military force, propaganda, and the defiance of long-established rules of international behavior, these states have been able to push their preferred policies through the community of nations—friends and foes alike.

Western Europe, because of its history, political tradition, and democratically adopted rules, does not act in this way. What is more, it has often been caught off guard in devising a response to adverse external behavior.

In a shift that has soured transatlantic relations since January 20, 2025, the United States has launched a policy that is openly hostile to its previous allies in Europe—a policy formally expressed in the November 2025 National Security Strategy. After their initial disbelief, European governments seem to have found ways to react collectively, although they remain vulnerable to personal attacks and are not always united.

Western European powers can only fight back within their own legal architecture, which is based on the rule of law, national constitutions, successive EU treaties, the conventions and protocols of the Council of Europe, and the procedures that govern European foreign policy decisions.

When it comes to possible external interference in the OCTs, the reactions of Western European governments will, of course, depend on each specific case. In some of the territories, such as New Caledonia, any such interference is a strictly national and hypothetical matter; in some, such as the British Indian Ocean Territory, it involves only a handful of interlocutors; and in others, such as Greenland, it involves one EU government and the relevant territory but, in legal terms, the entire EU as well. There is no single legal and diplomatic template to be applied.

But all disruptive actions against European OCTs have one set of features in common: They shake the legal foundations of European states, destabilize their political institutions, and, ultimately, fracture their democratic architectures. This is precisely why European governments—and the EU itself, when relevant—should systematically and firmly push back against such disruptive actions. No cajoling of or pandering to disruptive foreign forces will ever protect European democracy.

Marc Pierini is grateful to Lise Debraisne, a BA graduate in political science from Université Paris 8, who was tasked during her internship with Carnegie Europe in May–June 2026 with putting together data sheets for the thirty OCTs surveyed in this article. Her contribution formed an essential part of this analysis.