Is China exploiting South Korea's political crisis?

China has installed a large floating structure in waters that it disputes with South Korea, with analysts suggesting that the Chinese government is employing similar tactics to take control of territory as it used successfully to seize atolls and islets in the South China Sea over a decade ago.

China has placed similar steel structures in the same area in the past, insisting that they are merely "fishing support facilities" and each time leading to diplomatic protests from South Korea's government.

However, The Chosun Ilbo, a South Korean newspaper, cited diplomatic sources suggesting that China aims to advance its claims to the ocean territory amid South Korea's political chaos following President Yoon Suk-yeon's brief declaration of martial law in early December.

"It is being reported that the Chinese are building this structure, and they say it is for fishing, but at this point, the Korean side does not understand its purpose, whether it is for fishing, for military purposes or some other reason," said Kim Suk-kyoon, a professor at the Korea Institute of Maritime Strategy.

Disputed sovereignty

The Chinese construction, estimated from satellite images to be about 50 meters across and 50 meters high, is in the Provisional Measures Zone in the West Sea — which China refers to as the Yellow Sea.

The two nations dispute sovereignty over the waters, but fishing boats can operate in the area under a 2001 agreement signed between China and South Korea.

Kim told DW that the agreement expressly forbids the construction of facilities or searching for or developing other resources in the area.

"The maritime borders have not been settled in this area, so the provisional zone was set up," he said. "Under the agreement, neither country is permitted to take any actions that might impair the integrity of the other's claims, which means that China's construction of facilities is in breach of the fisheries agreement and international law."

The situation is complicated by talks on the median line and confirming the two sides' areas being on hold, while China in 2010 declared the area to be its "internal waters."

"China is using these structures to claim jurisdiction beyond the median line between the two countries and take a larger area," Kim said. "This is just one way to boost their claim."

Natural resources and overlapping claims

Rah Jong-yil, a former South Korean diplomat, believes China is motivated by reports that large oil deposits lie beneath the disputed area's seabed.

"When this sort of thing happened in the past, Seoul was always quick to lodge a diplomatic protest with China," he told DW.

Rah points out that a strongly worded complaint was sent to Beijing in April 2022, shortly before Yoon was sworn in as president and was a move seen as an early indication of China's intentions.

"China has again built a structure, despite knowing that it is in breach of the agreements, and I am confident Seoul will have made a complaint, but I see no signs of them backing down on this occasion," he said.

Dan Pinkston, a professor of international relations at the Seoul campus of Troy University, suggests that South Korea is not entirely without blame in the same area as it has constructed a maritime research station directly above a submerged sea mount in the West Sea known in Korea as Ieodo.

China has protested that as the feature is below the surface, international maritime law states that it cannot support human life and, therefore, cannot be used by a nation to extend its territorial waters.

The sea mount is 149 kilometers (93 miles) from the nearest South Korean land and 287 kilometers from Chinese territory, although both nations lay claim to the waters.

"China took the islands in the South China Sea in defiance of UN Convention on the Law of the Sea and then ignored an arbitration ruling by the court in The Hague," said Pinkston.

"South Korea's concern is that Beijing is simply going to replicate that playbook in this area, that it will start building more structures and use that to stake its own territorial claim, no matter what Korea says."

Multiple territorial disputes

Analysts note that China has a series of territorial claims against its neighbors, both on land and at sea.

China claims uninhabited islands controlled by Japan in the East China Sea should come under its control and has repeatedly confirmed that it intends to assimilate all of Taiwan.

It has made further claims in the South China Sea that are bringing it into confrontation with the Philippines, Vietnam, Indonesia and Malaysia.

On land, Chinese troops have clashed on the frontier with India, and China has nibbled away strategically important border regions belonging to Bhutan.

Analysts downplay claims that China is taking advantage of South Korea's political turmoil, where attention is almost entirely focused on efforts to impeach Yoon and the opposition parties' demands for fresh elections to seize a larger portion of the disputed waters.

"It would take time to plan and implement something like this, particularly in the maritime environment, so I do not believe it was deliberately linked to the problems in Korea today," said Kim.

"China has been making these claims for many years, and this is just one more step for them as they try to boost their claims."

Edited by: Keith Walker