These issues raise a series of challenges for Congress, including broad oversight of the Obama Administration's policies in Asia, decisions about military priorities and resources in and around disputed areas, how deeply to support the development of military capabilities of disputant nations, and how to manage relations with parties involved in the disputes, particularly China, Japan, the Philippines, and Vietnam, which have been involved in increasingly frequent maritime incidents in the East China Sea and South China Sea. Although the People's Republic of China (PRC) is not the only nation that has sought to press its maritime territorial claims, actions taken by PRC actors, including China's maritime law enforcement authorities and the People's Liberation Army (PLA), have been a particular concern. The former include the competing claims by China, Japan, and Taiwan over a set of Japanese-controlled islets called the Senkakus by Japan, the Diaoyu Islands by China, and the Diaoyutai Islands by Taiwan. Other disputes involve Japan and South Korea in the Sea of Japan, and China and South Korea in the Yellow Sea. However, U.S. government officials regularly voice U.S. opposition to the use of force, threat, or coercion by nations seeking to strengthen sovereignty claims over landmasses, and support for the use of customary international law and available arbitration mechanisms to resolve disputes peacefully. They have become one of the most challenging aspects of U.S. policy in Asia, touching on the management of treaty alliances, particularly those with Japan and the Philippines, where treaty obligations could be invoked if either country becomes involved in an active conflict with another of the claimants (for more, see the " Treaty Obligations " section below), and on the Obama Administration's efforts to help Asian nations build regional "rules and norms" that foster stability. Long-standing U.S. policy holds that the United States has no territorial claims in the region and does not take a position on any of the specific sovereignty disputes, but that it supports freedom of navigation in these waters and opposes the use of coercion, intimidation, threats, or force by claimants trying to assert their territorial claims. It has voiced particular support for discussions between China and ASEAN over a Code of Conduct for disputants in the region. Congress may choose to examine the rebalancing towards Asia and its implications for relations between China and other claimant nations. For example, Congress inserted in the FY2013 National Defense Authorization Act ( H.R. 167 ("Reaffirming the strong support of the United States for the peaceful resolution of territorial, sovereignty, and jurisdictional disputes in the Asia-Pacific maritime domains. "), which has been referred to the Senate Foreign Relations Committee. H.R. It has been referred to both the House Armed Services Committee and House Foreign Affairs Committee. The Senate also could offer its advice and consent to U.S. adherence to the United Nations Convention on the Law of the Sea (UNCLOS), which went into force in 1994 and is widely considered the governing regime for oceans and the primary (though not the only) venue for making maritime territorial claims and adjudicating maritime territorial disputes. In March 2012, the commander of a PLA Navy submarine base discussed the South China Sea as China's "maritime national territory" and called the nine-dash line China's "intermittent national boundary in the South China Sea," while stating that actions to assert China's jurisdiction were needed to support the marking of the national boundary. There are, however, some examples of exploration and development that have taken place in disputed areas. The frequency of Chinese maritime patrols in these waters has increased. U.S. Indonesian Ambassador to the United States Dino Djalal, for instance, said at a 2011 conference in Washington, DC, that given the priority the United States has placed on maritime security in East Asia, becoming a party to UNCLOS "has become a matter of strategic necessity—I repeat, strategic necessity, for the United States…"
On the broadest level, becoming a party to the Convention would give the United States a seat at the table at UNCLOS bodies, and give it the opportunity to influence experts from other nations in consideration of issues before the Convention. Selected Legislation on Asian Maritime Disputes in the 112th and 113th Congresses

In the 113 th Congress, on July 27, 2013, the Senate passed one resolution ( S.Res. Senator Menendez introduced another resolution ( S.Res. In November 2012, the Senate unanimously accepted an amendment introduced by Senator Webb to the National Defense Authorization Act for Fiscal Year 2013 ( S. 1253 ) that expressed the sense of the Senate regarding the East China Sea disputes, calling for parties to refrain from coercion and stating that the U.S.-Japan Treaty of Mutual Cooperation and Security covers areas under Japanese administration, such as the Senkakus. 4310 / P.L. 112-239 ).
Rising tensions stemming from maritime territorial disputes in East Asia have become a pressing challenge for U.S. policy makers, and pose one of the most complicated issues for the Obama Administration's policy of strategic "rebalancing" towards the Asia-Pacific.
Since around 2005-2006, long-disputed waters and land features in the South China Sea and, more recently, the East China Sea have seen increasingly aggressive behavior from nations trying to strengthen claims to disputed areas. Although China is not the only nation that has sought to press its maritime territorial claims, actions taken by People's Republic of China (PRC) actors, including its maritime law enforcement authorities and the People's Liberation Army (PLA), have been a particular concern. Chinese maritime authorities have taken actions include harassing vessels, destroying equipment, and blockading islets and shoals. Observers are concerned that the increasing frequency of such events raises the possibility of miscalculations that could lead to overt conflict at sea.
In the South China Sea, the PRC makes extensive claims, including marking on its maps an ambiguous "nine dash line" that covers approximately 80% of the sea, including the Spratly and Paracel island groups and other features such as Scarborough Shoal. These claims overlap with those of four Southeast Asian nations—Brunei, Malaysia, the Philippines, and Vietnam, which themselves have claims that conflict with each other. Taiwan also makes extensive claims mirroring those of the PRC. In the East China Sea, China, Japan, and Taiwan all claim a Japan-administered island group that Japan calls the Senkakus, China the Diaoyu Islands, and Taiwan the Diaoyutai Islands. Other territorial disputes exist between Japan and South Korea in the Sea of Japan, and between China and South Korea in the Yellow Sea.
Although the United States has no territorial claim in these waters and does not take a position on the various sovereignty disputes, it is long-standing U.S. policy to oppose the use of force, threat, or coercion to promote sovereignty claims, and to support the use of international law, including arbitration mechanisms, to resolve disputes peacefully.
The ability of the disputing countries, and of the United States and other parties, to manage tensions touches on numerous U.S. interests including
maintaining peace and stability among maritime nations in the Asia-Pacific; protecting free and unimpeded lawful commerce along some of the world's busiest maritime trade routes; protecting the U.S. Navy's ability to operate in these areas; managing U.S. treaty alliances with nations involved in the disputes; encouraging rules-based regional norms that discourage coercion or the use of force; and avoiding intimidation of U.S. companies that may seek to operate in the region.
The 113th Congress has held several hearings on the issues surrounding maritime disputes in East Asia. In 2013, the Senate unanimously passed a resolution (S.Res. 167) which expressed strong support of the United States for the peaceful resolution of territorial, sovereignty, and jurisdictional disputes in the Asia-Pacific maritime domains. In the FY2013 National Defense Authorization Act (H.R. 4310/P.L. 112-239), Congress stated its position that the Senkakus are administered by Japan, and that no acts of other nations will change their status. Another resolution, S.Res. 412, has been referred to the Senate Foreign Relations Committee. In the House, H.R. 4495 has been referred to the Committee on Armed Services and the Committee on Foreign Affairs.
There are other issues relating to East Asian maritime disputes that the 113th Congress may choose to address. The Senate may consider offering its advice and consent on the United States becoming a party to the United Nations Convention on the Law of the Sea (UNCLOS). Congress also may choose to examine the economic and security implications of a greater U.S. military presence in disputed areas, or the merits of providing additional resources to Southeast Asian nations to monitor and police their maritime domains. It also may choose to support efforts to lower tensions, including discussions between China and the Association of Southeast Asian Nations (ASEAN) on a Code of Conduct for parties in the South China Sea.