The policy of the United States and its close allies in the South China Sea has failed. Repeated statements of limited interest accompanied by occasional ship and aircraft passages have failed to prevent Beijing’s program of island creation, nor have they meaningfully forestalled China’s quest for military dominance in the region.

What should the Trump administration do about Beijing’s adventurism in the South China Sea? China is asserting sovereignty over some 80 percent of this strategic waterway and reinforcing its claim by maintaining by far the largest military, coastguard and maritime militia presence in the region.

According to a study from the Center for Strategic and Budgetary Assessments (CSBA), China has put installations on four islands in the Paracel group and significant installations on eight islands in the Spratly group. As before, China moved incrementally to avoid triggering a major Western reaction. The Obama administration has taken a few symbolic steps to defend freedom of navigation in the region, but they have had no evident effect on Chinese behavior. On Thursday, China’s navy seized an underwater drone collecting data for a U.S. Navy oceanographic vessel.

According to the Washington-based Centre for Strategic and Budgetary Assessments, China has “by far the largest military, coastguard, and maritime militia presence in the region — they are deploying strong surveillance, anti-air, anti-shipping, and strike forces onto the artificial islands they occupy — and they are actively intimidating other parties in the area”. Report author and former senior Australian Defence Department official Ross Babbage argues the Federal Government must take stronger action in response. “Our northern approaches are becoming much more questionable,” Professor Babbage told the ABC. “Ever since the Second World War we’ve assumed the United States and its close allies have really dominated the maritime environment — I’m afraid that’s really no longer the case.”

What should the U.S. and its close allies do about China’s strategic expansion into the South China Sea

President Obama failed to strongly challenge China's "adventurism" in the South China Sea, and now President-elect Trump must get tough with Beijing to reverse the country's "effective control over one of the world's most important strategic waterways," a new report says.