President Obama met with his counterpart from China last week as leaders from 51 nations gathered for a nuclear security summit in a world rattled by terrorist attacks and the specter that a nuclear device really could end up in the hands of extremists who will stop at nothing to achieve their insane agendas.

Obama's private meeting with Xi Jinping was held against a backdrop of increasingly tense relations in the Pacific, with China's leadership seemingly intent on provoking conflict with its neighbors, including the Philippines, Japan and South Korea, while daring the US to act.

Simmering tensions between the US and China are encapsulated in the showdown over China's military buildup of territory in the South China Sea, areas well outside its authority and in fact the legal claim of other countries. The US, to project its support for open seas and to show the flag for its allies, has sent warships and aircraft to conduct "freedom of navigation" patrols through areas being claimed by China.

The question is, what more can be done should China continue to defy calls to cease the buildup and adhere to international law? American resolve will be tested in May, when the Permanent Court of Arbitration in the Hague will rule on a lawsuit brought by the Philippines that contests China's claims to vast areas of the South China Sea and, in particular, to the seizure of the Scarborough Shoals, long claimed by the Philippines.

Experts predict the court will invalidate China's so-called "nine-dash-line" that is the basis for its territorial claims and rule that China's man-made islands in the area are illegal.

Few, if any, expect China to accept any adverse ruling.

The US and its allies may respond with tough new sanctions and trade rules to address continued aggressions. Handled carefully, that could ultimately prompt China to ease off, which it would do in a manner aimed at saving face. But any long-term solution will require a strategy worked with regional leaders, who together will assert control through robust joint capabilities and economic and legal means to convince China that continuing on its current course in the South China Sea is not in the nation's long-term best interest.

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