Even for the South China Sea, where territorial disputes are hardly uncommon, it has been an eventful, and rancorous start to 2016.
As members of the Association of Southeast Asian Nations met with U.S. President Barack Obama last week, reports surfaced that China has deployed surface-to-air missiles on one of the disputed Paracel Islands (known as the Xisha in Chinese). Beijing said the move is part of long-standing national defence policies on its sovereign territory.
"China's move of setting up limited, necessary and self-defence facilities on the islands and reefs where Chinese troops are stationed is in line with the right of self-defence endowed by international law to any sovereign state," Chinese foreign minister Wang Yi said on state-run TV. "Therefore there is nothing wrong with it."
That answer is unlikely to appease other nations with territorial claims in the area (including Taiwan, Vietnam, Malaysia, Brunei and the Philippines) or Washington, which has been adamant about maintaining navigational freedom in the South China Sea, as well as curbing Beijing's new assertiveness in the Asia-Pacific.
The various territorial disputes have spilled over into the regional economy in recent years. The South China Sea is one of the world's most vital shipping lanes, with as much as a third of global trade moving through the body of water.
And the strategic value of the islands cannot be understated. They will either give Beijing full access and control of the western Pacific, or for Washington and its allies create a containment line.
The issue facing Washington is getting its regional partners to agree on a common purpose. At the summit last week in California, Obama pressed the 10-member ASEAN to issue a joint statement, specifically calling on China to act in accordance with international mediation mechanisms.
"We obviously have issued such statements in the past with ASEAN," said U.S. National Security Advisor Susan Rice last Monday, before the summit. "And in it we consistently underscored our shared commitment to a peaceful resolution of disputes, freedom of commerce and navigation, the rule of law �"
This summit, however, did not result in such a statement. Instead, ASEAN agreed on the peaceful and legal resolution to South China Sea disputes, but without singling out China. While some observers noted that this was less than what the United States wanted, others said the statement achieved what Washington was looking for within reasonable parameters.
"If one looks at the paragraphs in the U.S.-ASEAN joint statement ... relating to the South China Sea, that modest but realistic expectation - broad agreement on a set of principles - was met," wrote Prashanth Parameswaran, the associate editor of Washington-based The Diplomat.
"To be sure, U.S. officials would prefer an even stronger stance by ASEAN on the South China Sea. The point here is simply that what was achieved within constraints was still quite significant."
The response from Beijing was predictably stark. Foreign ministry spokesman Hong Lei noted that Washington is only indirectly involved in these sovereignty disputes, saying that "relevant countries from outside the region should not flex their military muscles in the South China Sea and should not entice countries in the region to carry out joint military exercises or patrol activities targeting a third party."