Congress' ongoing interest in America's strategic and defense relationships in the Asia-Pacific region was reflected in a September 2006 House International Relations Subcommittee on Asia and the Pacific hearing on America and Asia in a Changing World. That hearing sought to review the main strands of U.S. policy in the Asia-Pacific, with the goal of conducting a net assessment of current and future strategic prospects in the region. This report, which focuses on America's strategic and defense relationships in the Asia-Pacific region, is written to assist congressional decision-makers concerned with such issues. It is also written as a companion piece to CRS Report RL33653, East Asian Regional Architecture: New Economic and Security Arrangements and U.S. Policy , by [author name scrubbed]. Former Chairman Jim Leach of the House Subcommittee on Asia and the Pacific observed that "it is in Asia where the United States will face its largest geopolitical challenges in the years ahead." He also noted that "maintaining a robust overseas military presence has historically been a key element of the United States national security policy in the Asia-Pacific." This forward presence promotes regional stability and "has been maintained by successive U.S. Administrations, all of which have emphasized the linkage between our network of alliances and friendships to a regional environment in Asia conducive to confidence in economic growth." The United States established a number of bilateral defense alliances with key Asian states in the 1950s as it was positioning itself to contain communist expansion in Asia in the period following World War II and the Korean War. Despite periods of drift, these alliance relationships provided support and assistance to the United States through the Cold War and during the war in Vietnam. The circumstances under which these alliances were forged have changed dramatically. The fall of the Soviet Union, the post-Cold War world, the Asian financial crisis, the rise of China, and the emergence of violent Islamist extremists have all done much to significantly alter the geopolitical landscape of Asia. A survey and assessment of the United States strategic and defense relationships in Asia may be of use given important shifts in the geopolitical dynamics of Asia. Such a review has led to several key shifts in the positioning of U.S. Asia-Pacific based forces including the anticipated shifting of some 8,000 marines from Okinawa to Guam, the reduction and repositioning of U.S. forces in South Korea away from the demilitarized zone dividing the peninsula, and an increase of additional naval and air forces on Guam. Most regional states continue to welcome the positive role that the United States can play in promoting regional security but some are beginning to hedge against what they perceive as an increasingly distracted and insufficiently engaged American power. Regional states' geographic proximity to China and rapidly expanding trade ties with China are, when combined with perceptions of American inattention, shifting regional states' perceptions of the long term role of the United States in the region. A recent study on the United States and Asia suggests that "Washington must actively re-engage if it is to maintain its influence" in the region. The United States' relative lack of attention to Asia comes at a time when the correlates of power are shifting not only with regard to China but elsewhere in Asia as well. Friction in the Sino-Japanese relationship as well as in North Korea-Japan relations is prompting Japan to develop its military capabilities and play a more assertive role in international affairs. India is developing rapidly and may as a result play an increasingly influential role in Asian and world affairs. South Korea may be developing capabilities that look to strategic scenarios other than those involving North Korea at a time when its alliance relationship with the United States is increasingly strained. Indonesia appears to be emerging from a lengthy period of economic and political instability as an increasingly effective democratic nation. These developments present both challenges and opportunities to the United States. Several key strategic issues in the Asia-Pacific region are potentially of concern to U.S. decision makers. These developments include the rise of China, continuing potential for interstate conflict, the struggle against Islamist militancy, and Asia-Pacific arms expenditures. China's rapid economic growth and its emergence as a great power is a defining event in the current geopolitical landscape of Asia. The United States hopes that engagement and economic development will lead China to become increasingly democratic and a stakeholder in global economic and political affairs. While the United States is hedging against the possibility that China's rise will be less benign, it welcomes a peaceful and prosperous China. In this context, the U.S. has sought to strengthen existing alliances and develop new strategic and defense relationships in the region while better positioning its regional military capabilities by restructuring and redeploying its forces in the region. Ongoing tensions over Taiwan, stemming from Beijing's opposition to Taiwanese independence, China's military modernization, its growing power projection capabilities, its expanding diplomatic relationships, its massive economic presence, and its drive for energy and other resources are of increasing concern among many in strategic circles in the United States. The Pentagon's Quadrennial Defense Review of 2006 and its 2006 annual report to Congress on China's military power noted that "China has the greatest potential to compete militarily with the United States." Most view the expansion of China's military power as primarily concerned with Taiwan, though some have noted that China is in the early stages of "developing power projection for ... contingencies other than Taiwan." Observers believe that China is seeking to attain a maritime anti-access force that could deter or delay the intervention of U.S. forces in a possible conflict over Taiwan. Some have taken the view that "China's leaders likely hope to establish their country as the preponderant power in East Asia." Such a view is at odds with the U.S. goal of preventing the Asian continent from being dominated by any single power or coalition of states that could potentially undermine American interests in the region. As much of the world enters a phase in which conflict is predominately at the sub-national level, Asia continues to have the very real prospect of interstate conflict. This is most likely in three areas: between China and Taiwan, on the Korean Peninsula, and between India and Pakistan. This potential for interstate conflict is reflected in regional arms sales. India, China, Taiwan, South Korea, and Pakistan are among the top 10 leading recipients of arms transfer in the developing world for the period 1998 to 2005. (See Table A-4 .) Tensions also exist between Japan and China, and between Korea and Japan. Potential conflict over Taiwan remains the most plausible scenario in which the United States could become embroiled in great power conflict. President Chen Shui-bian of the Democratic Progressive Party (DPP) has asserted a more independent stance for Taiwan than his Nationalist party (KMT) predecessors. In 2001, President Bush stated that the United States would do "whatever it takes" to help Taiwan defend itself, but later backed off from this assertion by warning Taiwan that the U.S. does not wish to see destabilizing declarations of Taiwan's independence that could provoke a conflict with China. Tensions on the Korean Peninsula increased in July and October 2006 as a result of North Korea's missile and nuclear tests. These events, along with North Korea's development of long range missiles, demonstrates that North Korea continues to seek to acquire new and increasingly lethal military capabilities. Ongoing tensions on the Korean Peninsula make it one of the world's most likely potential areas of interstate conflict. India's and Pakistan's history of war and ongoing tension make future conflict on the sub-continent a possibility. The two states fought wars in 1947, 1965, and 1971. In 1998, border tensions mounted in the wake of nuclear tests by both India and Pakistan, and the two states had a major border clash at Kargil in Kashmir in 1999. The two came close to war in 2001-2002 following the December 13, 2001, attack on the Indian parliament that is thought to have been carried out by the Pakistan-based terrorist groups Lashkar-e-Toiba and Jaish-e-Muhammad. The United States placed these groups on its terrorist list after the attacks. Differences between Muslim Pakistan and secular but largely Hindu India continue. Tensions increased in July 2006 after a series of train blasts in Bombay killed186 people. Bombay police have concluded that the attacks were planned by Pakistan's Inter Service Intelligence (ISI) and carried out by the Pakistan-based terrorist group Lashkar-e-Toiba. Such events place pressure on the Government of India to respond. They also identify a potential nexus between terrorism and interstate conflict. Such situations, or border conflicts such as at Kargil, have the potential to escalate into full-scale war between these two nuclear-armed states. Radical Islamist groups in Southeast Asia have carried out a number of deadly bombings since 9/11, including the Bali bombings of October 2002 and October 2005 and an attack on the Australian Embassy in Jakarta in 2004 by the terrorist group Jemaah Islamiya (JI). While counter-terror efforts have been increasingly successful, JI is thought to remain capable of conducting operations. The terrorist group Abu Sayaff also remains active in the Philippines. A regional maritime security initiative has sought to prevent attacks against shipping or ports, particularly in or near the strategically important Straits of Malacca, a maritime gateway through which much of the world's trade passes. Insurrection in Muslim majority provinces of Southern Thailand continues, although its ties to international terrorist groups have not been established. Similarly, the presence of terrorist groups in South Asia is a key source of instability, a threat to U.S. forces and interests, and could serve as a catalyst for inter-state conflict. Al Qaeda and Taliban forces remain active in the Afghanistan-Pakistan border regions.