Recent skirmishes between India and Pakistan in Kashmir have brought the two nuclear-powered nations closer to conflict than any time in recent memory.

The Islamic State of Iraq and Syria (ISIS) is losing its last patches of territory in Syria, which likely means its remaining fighters will spread out across the Middle East and beyond.

Sino-Indian rivalries in Maldives and other South Asian states is heating up as China projects power in the Indian Ocean region in unprecedented ways. Peace is elusive as ever in war-torn Afghanistan.

All of these regional hotspots have one thing in common for the United States: Diego Garcia.

The US coordinates most of its military operations in the Middle East and Afghanistan from the sub-equatorial atoll. It also uses Diego Garcia to monitor strategically important sea lanes between Asia, Africa and Europe.

But that remote and strategic outpost could face an unanticipated threat if a recent International Court of Justice (ICJ) advisory opinion eventually leads to a legally binding ruling.

The ICJ said in late February that the UK’s expulsion of people on the then Chagos Islands, including Diego Garcia, contravened international law and recommended that the UK “end its administration of the [archipelago] as rapidly as possible.”

The Chagos Archipelago, now known as the British Indian Ocean Territory (BIOT), is the UK’s last possession east of Suez. It was separated from the British colony of Mauritius in 1965, three years before the island nation became independent.

Between 1967 and 1973, the BIOT’s entire population of between 1,500 and 2,000 people, mostly a Creole speaking mix of Indians and Africans who survived by growing coconuts and collecting guano, was deported to Mauritius or Seychelles, both situated more than 1,000 miles away.

US military personnel arrived on the main atoll of Diego Garcia in March 1971, bringing with them earth-moving gear, building materials and workers, of whom many were Filipinos, to build a military base which is now among its most important worldwide.

In 1966, the UK and US signed an agreement known as the “Availability of Certain Indian Ocean Islands for Defense Purposes” that did not specify the nature of activities that would be conducted on the islands.

According to David Vine, an American academic, the agreement was signed “under the cover of darkness” without congressional or parliamentary oversight.

It soon became clear, however, what the agreement was all about. Diego Garcia surrounds a lagoon that is 24 kilometers long, 6.4 kilometers wide and nearly ten meters deep. With some dredging and digging, a deep-water harbor was built.

Modern houses connected by paved roads were built next on the atoll, as was a runway long enough for huge military aircraft to land. Diego Garcia quickly began to resemble other foreign US military bases, though without a potentially restive local population nearby.

The choice of Diego Garcia was in line with a US policy known at the time as the “Strategic Islands Concept”, which aimed to establish military bases away from populous mainland areas where they could be exposed to anti-Western local opposition.

It was later revealed that the UK had agreed in 1966 to lease Diego Garcia to the US for 50 years. That agreement expired in 2016, but the UK opted to grant the US a further 20-year lease for Diego Garcia. There are between 3,000 to 5,000 soldiers and civilians based there at any given time.

While Diego Garcia is smaller than America’s bases in South Korea, Japan and Germany, its strategic importance is likely greater due to its location to key regional hotspots and China’s rising forays into the Indian Ocean region.

No outsiders are allowed to enter the base, which reports indicate resembles an American suburb, with well-stocked supermarkets, hamburger joints, beer bars, tennis courts, jogging tracks and satellite TV.

Diego Garcia earned notoriety during President George W Bush’s so-called “war on terror” when it was revealed as one of the “black sites” where terror suspects, including from Afghanistan, were detained and interrogated.

The Qatar-based news organization Al-Jazeera reported that Diego Garcia had in 2002 and 2003 been used for what was euphemistically called “extraordinary rendition”, or the transfer of detainees without legal process, with the full cooperation of British authorities. Reports of torture of detainees on Diego Garcia also later emerged.

But a problem unforeseen in the 1960s has cropped up from the people who were forcibly expelled from the islands and resettled in Mauritius and Seychelles. While they were given monetary compensation at the time, many are fighting for their right to return home.

The Chagossians, now numbering about 6,000 including descendants of the original inhabitants, have won the sympathy and support of global human rights groups, with some now providing legal assistance to raise the issue in international courts and fora.

The Chagossians’ cause has evolved into a major international issue involving British courts, the United Nations, the European Court of Human Rights and the Permanent Court of Arbitration at The Hague, among others.

Mauritian politicians have also started to grandstand on how their predecessors were forced to give up the Chagos Archipelago, in what some now view as the UK using political blackmail to win control of the islands.

Information revealed in the ICJ’s advisory opinion revealed that the British told local leaders that they would not be allowed independence if they did not agree to cede the Chagos Archipelago.

In June 2017, the UN General Assembly voted 94 to 15 with 65 abstentions to ask the ICJ to issue an “advisory opinion” on whether the UK had lawfully adhered to the decolonization process when it separated the Chagos Archipelago from Mauritius.

The opinion, announced on February 25, is non-binding but urges the UK to give up the BIOT, which, in effect, would mean returning the islands to Mauritius. It seems likely that the aggrieved Chagossians will press their case further, though the ICJ has not released a timetable for legal procedures.

The British Foreign Office said it would “carefully” look at the ICJ’s advisory opinion while noting that it is “not legally binding. It noted that the defense facilities maintained their “help to protect people here in Britain and around the world from terrorist threats, organized crime and piracy.”

The ICJ’s judges said as part of their advisory opinion that all UN member states, including the US, are obliged to “cooperate to complete the decolonization of Mauritius.”

It’s not entirely clear how that may play out. Mauritius Defense Minister Anerood Jugnauth said at a hearing last year that his country “recognizes [Diego Garcia’s] existence and has repeatedly made it clear to the United States and the administering power that it accepts the future of the base.”

While such assurances may have been welcomed in Washington, the US would no doubt prefer to maintain its prevailing tried and trusted arrangement with the UK on its remote and isolated base.