In 2012, China wrested control of Scarborough Shoal in the South China Sea from the Philippines. With the shoal—reefs, rocks, and a vast lagoon—located just 220 km (137 miles) from the Philippines’ main island Luzon, the incident heightened tensions and embarrassed Manila, which the following year opened a case in an international tribunal challenging Beijing’s territorial moves in the sea. So alarm bells went off earlier this month when Chinese ships gathered at Sandy Cay, a set of sandbars close to Philippines-occupied Thitu Island in the sea’s Spratly archipelago. The island has a small civilian population and a decrepit runway the Philippines has been meaning to repair.

The flotilla was seen as intimidating at the very least. “China’s ongoing maritime activity around Thitu is worrisome… if the objective of the operation is to occupy Sandy Cay, that would mean a significant escalation in tension in the South China Sea. Asia has acquired yet another flashpoint it could well do without,” wrote Euan Graham, a security analyst with the Lowy Institute for International Policy in Sydney.

A number of nations have claims to various features in the Spratlys. China, for its part, claims nearly the entire sea for itself, based on its infamous nine-dash line. The tribunal invalidated that sweeping claim in a nearly 500-page ruling issued in July 2016, but Beijing dismissed the legal proceedings entirely.

Satellite images shared by the Center for Strategic and International Studies’ Asia Maritime Transparency Initiative, based in Washington, DC, confirmed the presence of the flotilla, which included fishing, coastguard, and navy ships. The Philippines military confirmed it as well. It’s unclear at the time of this writing whether the vessels are still present.

Why it’s on our radar: It’s not clear whether China is actually preparing to ‘acquire’ another land feature in the South China Sea at present or whether Beijing was merely testing the waters, pardon the pun, to gauge reactions from regional powers, most notably the Philippines. 

China is attempting to press its advantage after being able to essentially annex Scarborough Shoal in 2012, formerly Philppines territory, and recent moves by Filipino President Rodrigo Duterte to align more closely with Beijing while distancing his country from Washington. While some are advising Duterte to send Filipino warships to Sandy Cay and, if they are fired upon by the Chinese, to then invoke the mutual defense treaty with the U.S., Duterte has said in such a case, “I will not call on America. I have lost trust in the Americans.” 

Slowly and tactically, China is moving to spread its dominance and influence over the South China Sea. Beijing’s long game is to dominate as much of the region as possible — to edge out the United States and in so doing Washington’s ability to influence geopolitical events in the region. If Beijing’s moves continue to spark little-to-no response, it will continue acquiring, and likely fortifying, additional land masses that have long been in dispute.