Satellite photos of four "Y" shaped concrete structures being built on Taiping Island in the South China Sea administered by the Republic of China (Taiwan) suggests Taiwan anticipates an amphibious invasion of the island and is preparing to repel it.
An invasion can only come from mainland China although Beijing has so far shown no indications it plans to invade Taiping or Itu Aba Island, the largest in the disputed Spratly Islands.
Taiping, which is 1.4 km long, is 1,800 km from Taipei; 860 km from Manila; 1,200 km from Hainan and 850 km from Ho Chi Minh City. Taiwan, China, the Philippines and Vietnam all have claims on the Spratlys.
Taiwan media reports showed Google Maps images of four new structures built in the shape of tetrapods (commonly used to refer to bird feet) or the letter "Y." The structures weren't on Google Map photos of Taiping taken last January, indicating their construction began only a few months ago.
The structures might be from three to four stories tall and face the island's west coast. Some reports said the structures might be emplacements for heavy machine guns, anti-tank missiles or 40 mm anti-aircraft guns. The structures might also be used to house early warning radar and other communications facilities.
The structures are located along the shore on the west coast of Taiping, the likeliest place to land an amphibious invasion force. Behind the Y structures is a circular structure still under construction.
Taiwanese Defense Minister Feng Shih-kuan refused to reveal what the structures are for.
"It is inconvenient for us to reveal any military facilities we are installing on Taiping Island and what their purposes are as they are all considered secrets," said Feng.
He did, however, reassure Taiwanese that "Taiping Island has a strong defensive capability."
Some analysts said the towers resemble the massive "flak towers" or "flak turm" used by Nazi Germany to house heavy anti-aircraft guns that attempted to shoot down American and British bombers raining bombs on Germany.
Last July 12, a ruling by the Permanent Court of Arbitration in the case brought by the Philippines against China also led to the classification of Taiping Island as a "rock" under the United Nations Convention on the Law of the Sea.
This ruling means Taiping isn't entitled to a 200 nautical mile exclusive economic zone and continental shelf. Taiwan rejected this ruling.