china south china sea woody island
Why it's so tense in the South China Sea (2018)
01:17 - Source: CNN

Editor’s Note: The story was first published in October and has been updated to reflect the latest developments.

Story highlights

Tensions have ratcheted up in in the South China Sea.

China has a long history of maritime disputes with its South China Sea neighbors

CNN  — 

Dotted with small islands, reefs and shoals, the South China Sea is home to a string of messy territorial disputes that pit multiple countries against each other.

China’s “nine-dash line” – its claimed territorial waters that extend hundreds of miles to the south and east of its island province of Hainan – abut its neighbors’ claims and, in some cases, encroach upon them.

Tensions have ratcheted up as China has reclaimed land in massive dredging operations, turning sandbars into islands equipped with airfields, ports and lighthouses.

Beijing has also warned U.S. warships and military aircraft to stay away from these islands.

Who claims what?

Brunei, Malaysia, the Philippines, Taiwan and Vietnam all dispute sovereignty of several island chains and nearby waters in the South China Sea – with rival claims to the Chinese interpretation.

The Paracel Islands have been controlled by China since 1974 but they are also claimed by Vietnam and Taiwan. Tensions flared in 2014 when China installed exploratory oil rigs in the vicinity.

The situation is more complicated in the Spratlys, which Beijing calls the Nansha islands.

The archipelago consists of 100 smalls islands and reefs of which 45 are occupied by China, Malaysia, Vietnam or the Philippines.

All of the islands are claimed by China, Taiwan and Vietnam, while parts of them are claimed by the Philippines, Malaysia and Brunei.

China is actually relatively late to the party when it comes to occupying territory in the Spratly archipelago, starting its occupation of reefs and islands in the area in the 1980s.

Taiwan first occupied an island in the Spratlys after World War II, and the Philippines, Vietnam and Malaysia followed suit, and all have built outposts and airstrips on their claimed territory, according to Mira Rapp-Hooper, a Senior Fellow in Asia-Pacific Security Program at the Center for a New American Security (CNAS).

READ: Washington ‘not provoking’ China

What’s China been building?

Satellite imagery from 30 March, 7 August 2014 and 30 January 2015 shows the extent of Chinese progress in building an island at Gaven Reefs in the Spratly Islands.

In early 2014, China quietly began massive dredging operations centering on the seven reefs it controls in the Spratly Islands – Fiery Cross Reef, Subi Reef, Mischief Reef, Cuarteron Reef, Gaven Reef and Hughes Reef.

According to the U.S., China has reclaimed 3,000 acres since the beginning of 2014.

Vietnam, Malaysia, the Philippines and Taiwan have also reclaimed land in the South China Sea, but their land grab – the U.S. says approximately 100 acres over 45 years – is dwarfed by China’s massive, recent buildup.

In September 2015, during his trip to Washington, President Xi Jinping said China wouldn’t “militarize” the islands but is building three airstrips that analysts believe will be able to accommodate bombers, according to satellite images analyzed by the Washington-based Center for Strategic and International Studies (CSIS).

China has had a military presence on Woody Island, in the Paracels, for half a century and in February deployed surface-to-air missiles and fighter jets on the island.

The Philippines, which lies geographically closest to the Spratlys, has troops stationed in the area, as do other claimants. There are no indigenous inhabitants.

How has the U.S. responded?

The U.S. government takes no position on the territorial disputes in the South China Sea but it has called for an immediate end to land reclamation.

It also sails and flies its assets in the vicinity of the reclaimed islands, citing international law and freedom of movement.

In May 2015, it flew over man-made islands in the Spratlys with a CNN crew on board, triggering repeated warnings from the Chinese navy.

In October, it sent a warship, the USS Lassen, to within 12 nautical miles of Subi Reef. It conducted a similar Freedom of Navigation (FON) operation in January 2016.