More than ever, islands — and the resources beneath them — are the focus of geopolitical tensions between nations around the world.
The biggest disputes range from the Arctic to Croatia to north of Samoa, and some of the competing claims were made centuries ago.
Claims by Canada and Denmark
Canada and Denmark are currently going back and forth over who owns a small island in the Kennedy Channel, which separates Canada's Ellsmere Island from Greenland.
The dispute dates back to the 1980s when the Canadians and the Danes waged the 'Battle of the Bottles,' during which the Canadian and Danish navies would visit the island and leave bottles of Canadian Club whisky and Akvavit, a Scandinavian liquor, to mark their territory.
Things ramped up in the early 2000s when a Danish fleet descended on the island and planted a flag in the ground, a move that irked the Canadians. In July 2005, the Canadians responded with 'Exercise Frozen Beaver,' during which they erected a 12-foot flag.
Tensions settled shortly thereafter when the two governments released a joint statement saying 'all contact by either side with Hans Island will be carried out in a low key and restrained manner.'
Denmark and Canada are still trying to reach a mutual agreement regarding Hans Island.
Claims by Japan, China, and Taiwan
The Japanese government has been in control of Senkaku since it formally annexed the islands in 1895, excluding 1945 to 1972 when they were under US occupation authority, but China claims discovery and control of the islands since the 14th century.
The islands are uninhabited (one is used by the US military for drills) but are surrounded by rich fishing grounds.
In 2010 a Chinese fishing boat and a Japanese coast guard vessel collided near the islands, setting off a serious diplomatic spat in which Beijing temporarily froze trade and ministerial talks.
Since then the island has been at the center of rising tensions between the two Asian superpowers, with each releasing formal documents staking their claims last November.
Earlier this month the New York Times reported that Japan had scrambled its jets 943 times in a 12-month period between March 2014 and March 2015, rivaling Cold War levels. A majority of those scrambles were targeted at Chinese aircraft in the vicinity of the disputed islands.
On April 22, The New York Times reported that China's president, Xi Jinping, and Japan's prime minister, Shinzo Abe, met in Indonesia during a gathering of Asian and African nations. The meeting lasted about 30 minutes and while the issue of the islands was likely not broached, the meeting could help open a dialogue for the future.
Claims by China, Taiwan and Vietnam
The Paracel islands are a group of over 30 islets, sandbanks, and reefs that sit equidistant to China and Vietnam. They are inhabited by turtles as well as a small number of Chinese troops.
One of several disputes in the South China Sea, parts of the Paracel Islands were controlled by China and South Vietnam before tensions boiled over in 1974 and a conflict resulted in 71 soldiers being killed.
China has controlled all of the islands since then but Vietnam disputes the claim.
IHS Jane's Defence Weekly confirmed reports on April 16 that China is also building a military airstrip on the Paracel Islands to go along with the one it has built further south on the Spratly Islands. These developments have angered the United States and alarmed China's neighbours.
Claims by China, Taiwan, and the Phillipines
The shoal is a triangle-shaped chain of reefs and rocks located about 140 miles east of the Phillipines (and 400 miles southwest China) in a fishing-rich area. China and Taiwan claim that the Chinese people discovered the shoal centuries ago and that there is a long history of Chinese fishing activity in the area. The Phillipines claim they have occupied the island since gaining thier independence in 1898 and therefore have legal rights to the shoal based on criteria within the lawful methods for the acquisition of sovereignty.
Tensions boiled over in April 2012 when a Filipino surveillance plane spotted eight Chinese fishing vessels docked off the coast of the shoal with illegally collected corals, giant clams, and live sharks onboard. When the Filipino Navy attempted to arrest the fishermen they were blocked by Chinese Maritime Surveillance.
The two sides then had a tense standoff on the shoal until the US helped broker a deal for both sides to remove their forces from the island until a deal over its ownership could be reached. The Phillipines complied but China renegged on the deal, leaving their forces at the shoal and effectively militarizing it.
Since then Chinese Coastguard and Maritime Surveillance have been patrolling the waters around the shoal and turning away Filipino vessels spotted in the area. There have also been recent reports of Chinese vessels robbing Filipino fishermen at gunpoint and shooting water canons at them.
According to the Daily Mail, this month close to 12,000 Filipino and American soldiers kicked off expanded war drills, including an amphibious assault exercise, at a navy base facing Scarborough Shoal.
The exercise simulated retaking a Philippine island occupied by invaders.
Claims by Vietnam, China, Taiwan, Malaysia and the Philippines
The first contact with the Spratly Islands may have been as early as 600 BCE, when people migrated across the South China Sea.
Around the 17th century, both China and Vietnam charted and made claims to the islands, completely unaware that the other had done the same.
Itu Aba Island -- the only inhabitable island and the only one with a freshwater supply -- was claimed as part of French Indochina in 1887, turned into a submarine base by the Japanese during World War II, and placed under the administration of
Taiwan in 1946.
Itu Aba has no long-term inhabitants but is also claimed by China, the Philippines, and Vietnam because of its rich fishing grounds and potentially significant reserves of oil and natural gas.
Recent reports indicate that China has seriously ramped up efforts to establish a military base on the disputed islands. Based on satellite imagery from Airbus Defence and Space, the Chinese have been dredging three new islands within the Subei Cross Reef where the islands are located and have built a military-length runway.
The final construction of a runway at the Subei Reef is likely to antagonize the Philippines, as the reef is 'only 25 km from Thitu/Pagasa island, which is occupied by the Philippines and has a civilian population,' according to IHS Jane's Defence Weekly.
As of February 2015, Beijing has completed advanced stages of construction for six different island reefs throughout the sea with construction starting on a seventh, according to Reuters
The islands will serve as forward operating bases for the Chinese military. Once construction is complete, Beijing will be able to use the bases to project their military force throughout the South China Sea.
The expansion of Chinese construction in the South China Sea is kicking off a series of territorial disputes with Beijing's neighbours in the south, all of whom also have competing maritime claims to the reefs and islands.
Claims by the United Kingdom and Mauritius
The Chagos Islands are a remote group of seven atolls comprising more than 60 individual tropical islands in the Indian Ocean. The nearest landmass is the Maldives to the north.
The islands had been a part of the African island nation of Mauritus until the 18th century when French settlers began arriving. In 1810, the French ceded the island to Great Britain and in 1965 the UK split the Chagos Archipelago away from Mauritius to form the British Indian Ocean Territory.
In 1971 the UK leased the atoll of Diego Garcia to the United States to build a military base and kicked out the native Chagossians who lived on the island. Today, Diego Garcia is the only inhabited part of the Chagos Islands, and only by military and civilian-contracted personnel.
In April 2010, the British government established the Chagos Archipelago as the world's largest marine reserve in an apparent attempt to prevent any resettlement by the evicted natives, according to WikiLeaks. In December 2010 Mauritus filed charges against the UK under the United Nations Convention on the Law of the Sea (UNCLOS) to challenge the legality of the Marine Reserve.
Five years later the case has made it all the way to an international court of arbitration, where representatives from Mauritius and the UK are currently making their case to a UN tribunal in secret proceedings over the legality of the marine reserve.
Mauritius believes a ruling in their favour could lead to an unravelling of the UK's claim over the islands, allowing them to come back under Mauritius sovereignty.
Claims by Nicaragua and Costa Rica
Nicaragua and Costa Rica have been disputing the ownership of Calero Island for two centuries, but it's widely considered to be part of Costa Rica.
In November 2010 Nicaragua began dredging around Calero based on borders found on
Google Maps, which mistakenly labelled Calero Island as part of Nicaragua.
Nicaragua has refused to withdraw troops from the disputed land despite conceding that it occupied the area only because of the mistake by Google Maps.
In March 2011 the International Court of Justice provisionally ruled that both countries should refrain from maintaining civilians, security forces or police on the island, but that Costa Rica can send civilian teams concerned with environmental matters.
Since then the island has continued to be at the center of rising tensions between the two Central American nations, with accusations of encroachment made by both sides.
Now Nicaragua and Costa Rica are back at the International Court of Justice after Costa Rica accused Nicaragua of having a 'giant environmental impact' on the San Juan river, which runs along the northern side of the island, from the dredging it had done back in 2010.
Nicaragua denies the claims and says that the dredging is necessary in order to make the San Juan navigable.
Claims by Japan and South Korea
The Liancourt Rocks, known as Dokdo ('solitary island') in Korean and Takeshima ('bamboo island') in Japanese, consist of two main islets and 35 smaller rocks in the Sea of Japan.
A Korean octopus fisherman and his wife are permanent residents on the islets. A small Korean police detachment, administrative personnel, lighthouse staff, and the South Korean Coast Guard are stationed in nonpermanent supporting positions on the islets.
On April 14, 2015, two top defence and security officials from South Korea and Japan met for the first high-level 'two-plus-two' security talks in over five years, according to The Diplomat. The move was meant to herald an easing of tensions between the countries, but talks reportedly soured when Japan again asserted its claim over the Liancourt Rocks.
Both nations claim the island from several hundred years ago. Interestingly, North Korea supports South Korea's claim, despite still technically being at war with them.
Claims by Iran and United Arab Emirates (UAE)
Greater and Lesser Tunbs are two small islands in the Strait of Hormuz that have been claimed by both Persians and Arabs for centuries.
Currently the islands are inhabited mostly by Iranian military.
In April 2012, then Iranian President Mahmoud Ahmadinejad visited the island of Abu Musa, becoming the first Iranian head of state to do so since Tehran took over the island 41 years ago.
UAE then recalled its ambassador from Tehran for consultation and canceled a friendly soccer match with Iran, according to Arabian Business News.
At the Arab League Summit in March 2015, Iranian Foreign Ministry spokeswoman Marzieh Afkham reaffirmed Iran's sovereignty over the islands, saying 'these islands are an inseparable part of the Iranian territory.'
She added that, 'the repetition of interfering claims about Iran's sovereignty on the three islands will never have any impact on the existing legal and historical realities.'
Claims by Japan and Russia
In their first officially established relations, Russia and Japan agreed in 1855 that Japan owned the islands of Etorofu and Kunashiri. But Russia invaded the islands in 1945 and expelled the Japanese inhabitants.
Russian forces have administrated the islands ever since, despite sovereignty claims by Japan, which calls them the Northern Territories.
In 1951 the San Francisco Peace Treaty stipulated that Japan had to give up all claims to the islands, but it didn't explicitly recognise the Soviet Union's claim. Japan argues that some of the islands aren't part of the Kuril Islands so they aren't covered by the treaty.
In 2006, a Russian patrol boat opened fire on a Japanese fishing boat found illegally off the coast of the disputed islands after the vessel defied several orders to surrender. One Japanese fisherman was killed during the altercation.
In February 2015, Japanese Prime Minister Shinzo Abe vowed to reclaim the islands from Russian control during a holiday celebrating Japan's northern territories. Russia currently uses the island to preform military exercises.
Claims by United Kingdom and Argentina
The Falkland Islands comprise East Falkland, West Falkland, and 776 lesser islands.
The capital and only city is Stanley (population: 2,115) on East Falkland. The the islands are self-governing, but the archipelago is territory of the UK, which is responsible for its defence and foreign affairs
Portugal, Spain, and Britain all claimed to have discovered the islands in the 16th century; there have been French, British, Spanish, and Argentine settlements at various times.
The UK established its control in 1833 and Argentina has disputed the claim ever since, unsuccessfully invading the islands for two months in 1982 in what is unofficially known as the Falklands War.
Last month, British Defence Secretary Michael Fallon said that England plans to 'beef up' its defence of the islands. Argentina has also stepped up a campaign to get what it calls 'Las Malvinas' back.
The Sun newspaper reported that Russia was working on a deal to lease 12 long-range bombers to Argentina for a possible attempt to launch an offensive to reclaim the islands.
'That particular deal hasn't been confirmed,' Fallon said, saying a threat remained nonetheless. 'It is a very live threat, we have to respond to it,' he said.
There are about 3,000 Falkland Islanders, and they are British citizens.
Claims by Greece and Turkey
Imia/Kardak is a pair of small uninhabited islets in the Aegean Sea that sit between Greek island chains and the west coast of Turkey.
On December 27, 1995, the Turkish Foreign Ministry officially declared the islets Turkish territory. The next month, warships from both Turkey and Greece
sailed to the islets as special forces from Greece landed on the east islet and special forces from Turkey landed on the west islet, both undetected, to raise their respective flags.
The immediate military threat was defused primarily by the late US envoy, Richard Holbrooke, who spoke with officials of both countries over the phone during the final hours of the crisis.
Since then territorial disputes over islands in the Aegean Sea have smoldered, with Turkey laying claim to a large number of other islets in the Aegean that are considered to be of 'undetermined sovereignty' by Turkey, but are regarded as indisputably Greek by Greece.
Earlier this month, Turkey called on Greece to avoid unilateral action in the Aegean Sea if Athens does not want to harm the 'positive atmosphere' between the two countries.
The Aegean region has witnessed increasing tension between Turkey and Greece, which escalated after the election of the new Syriza government in Greece in January.
Turkey's comments came after Greek Defence Minister Panos Kammenos visited Imia/Kardak Island on January 30.
Claims by the US and Haiti
Navassa Island is about 2 square miles and is located 100 miles south of Guantanamo Bay, Cuba.
It was claimed for the US on September 19, 1857, by sea captain Peter Duncan, even though Haiti had previously claimed it.
The island was rich in guano, so around 1865 the US built mining facilities with housing for 140 contract laborers, houses for supervisors, a blacksmith shop, warehouses, and a church.
The island has been uninhabited since the end of WWII and has been the administrative responsibility of several US agencies, including the Coast Guard, the Department of the Interior, and most recently the Fish and Wildlife Service, which made Navassa Island a National Wildlife Refuge.
A 1998 scientific expedition led by the Center for Marine Conservation described Navassa as 'a unique preserve of Caribbean biodiversity.' The island's land and offshore ecosystems have survived the 20th century virtually untouched.
A group of radio operators were granted rare access to the island for a DX-pedition for two weeks in February 2015.
Claims by Spain and Morocco
Perejil Island lies within Moroccan territorial waters, just 220 yards off the Moroccan shore in the Strait of Gibraltar, but has been Spanish territory since 1668.
The small rocky island is sometimes used by local Moroccans as a goat pasture.
In 2002, Morocco sent a dozen soldiers to occupy the uninhabited island. Spanish soldiers subsequently evicted the them and re-established the Spanish flag without incident. The islet is now deserted but is monitored by both countries.
Claims by US and Canada
Machias Seal Island is located in the Gulf of Maine, about 10 miles southeast of Maine and 12 miles southwest of New Brunswick. Both the US and Canada claim ownership to it, as well as to neighbouring North Rock.
The island is currently designated as the Machias Seal Island Migratory Bird Sanctuary and is managed by the Canadian Wildlife Service.
The Canadian Coast Guard staffs a lighthouse on the island; until the 1980s lighthouse keepers would live on the island with their families and receive supplies by sea.
The US claim does not seem to be very strong as the only time it inhabited the island was in 1918 when it placed marines there (with Canadian consent) for a few months to protect the Bay of Fundy from German U-boat attacks.
Citizens of Maine have made claims, but the state of Maine has also referred to it as being owned by Canada.
Claims by Croatia and Serbia
Both the Island of Šarengrad and the Island of Vukovar are located on the Danube river on the border of Croatia and Serbia.
When Yugoslavia existed, both islands were part of Croatia. But during the Croatian War of Independence (1991-95), the Serbian militia occupied the islands.
In 2004, Serbia withdrew its troops from the islands but replaced them with police. Croatians can go to the islands, but Croatian land ownership is not recognised by Serbia.
The islands were opened up for recreational purposes in 2009, but Serbia still claims the islands because they are closer to the Serbian coast.
In a statement for the daily newspaper Novi List in February 2012, Croatian President Ivo Josipović said that the two countries need a flexible solution for border disputes on the Danube River and encouraged both sides to submit proposals.
According to an internationally recognised border, the islands are part of the Croatian state.
Claims by France and Madagascar
The Glorioso Islands became a French possession in 1892, but were first were named and settled in 1880 by Frenchman Hippolyte Caltaux (who established a coconut plantation). Today the archipelago is a nature reserve with a meteorological station garrisoned by the French Foreign Legion.
In 1897, France took control of Bassas da India, an uninhabited atoll known as a shipwreck hazard. In 1968, France placed it under the administration of a commissioner residing on the island of Réunion, which is the outermost region of the European Union and serves as an overseas department of France.
Juan de Nova Island (which is also a wreck risk) came under French control in 1897 and was exploited for guano deposits in the 20th century before being abandoned during WWII. It is considered an Important Bird Area by BirdLife International because it supports up to 100,000 breeding pairs of
Madagascar claims sovereignty over the territories.
Claims by U.S. and New Zealand
Swains Island is an atoll north of Samoa in the Pacific Ocean that is considered an unincorporated unorganized territory of the U.S. and is administered by American Samoa. It is part of the Tokelau chain, which is territory of New Zealand.
Swains Island has a population of 37 Tokelauans who harvest the island's coconuts.
In 1856, Eli Hutchinson Jennings, and American, claimed to have received the title to the atoll from Captain Turnbull of the UK and joined a community of Swains with his Samoan wife. He set up a coconut plantation and the Jennings family ruled Swains Island virtually independent of any outside authority from 1856 until 1925, when the island came under the jurisdiction of American Samoa.
On March 25, 1981, New Zealand confirmed US sovereignty over Swains Island in the Treaty of Tokehega, but a 2006 referendum referred to Swains Island as part of Tokelau (i.e. New Zealand).
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