Naval Sea Systems Command

US-Japan Alliance
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TOKYO, Japan: Chief of Naval Operations (CNO) Adm. Jonathan Greenert is escorted by a troop commander as he performs a customary troop inspection at a full honors ceremony to welcome Greenert and his delegation to Japan upon their arrival at the Japanese Ministry of Defense for a series of counterpart visits with Japanese political and military leaders. During Greenert's visit to Japan he also conducted U.S. Navy fleet engagement activities at Yokosuka Naval Base and Naval Air Facility Atsugi. (U.S. Navy photo by Chief Mass Communication Specialist Peter D. Lawlor/Released)

Japan is one of the world’s most successful democracies and largest economies. The U.S.-Japan alliance is a cornerstone of U.S. security interests in Asia and is fundamental to regional stability and prosperity. It is based on shared vital interests and values. These include stability in the Asia-Pacific region, the preservation and promotion of political and economic freedoms, support for human rights and democratic institutions, and securing of prosperity for the people of both countries and the international community as a whole.

Japan provides bases and other support to U.S. forward-deployed forces that are essential for maintaining stability in the region. Over the past decade, the alliance has been strengthened through revised defense guidelines that better define Japan's noncombatant role in a regional contingency, the renewal of the agreement on host nation support of U.S. forces forward deployed to Japan, and the Defense Policy Review Initiative (DPRI). The DPRI redefines roles, missions, and capabilities of alliance forces and outlines key realignment and transformation initiatives, including reducing the number of U.S. troops stationed in Okinawa, enhancing interoperability and communication, and broadening cooperation in the area of ballistic missile defense.

Because of the two countries' combined economic and technological impact on the world, the U.S.-Japan relationship has become global in scope. The United States and Japan cooperate on a broad range of global issues, including development assistance, combating communicable disease, and protecting the environment and natural resources. The countries also collaborate in science and technology in such areas as mapping the human genome, research on aging, and international space exploration.

Japan contributes irreplaceable political, financial, and moral support to U.S.-Japan diplomatic efforts. The United States consults closely with Japan and the Republic of Korea on policy regarding North Korea. The United States works closely with Japan and Australia under the auspices of the Trilateral Strategic Dialogue and the Security and Defense Cooperation Forum to exchange views and increase coordination on global and regional initiatives. In Southeast Asia, U.S.-Japan cooperation is vital for stability and for political and economic reform. Outside Asia, Japanese political and financial support has substantially strengthened the U.S. position on a variety of global issues, including terrorism in all its forms, working to stop the spread of epidemics, advancing environmental and climate change goals, maintaining solidarity in the face of rising challenges, assisting developing countries, countering piracy, and standing up for human rights and democracy. Japan is an indispensable partner in the United Nations. Japan broadly supports the United States on nonproliferation and nuclear issues.

The United States established diplomatic relations with Japan in 1858. During World War II, diplomatic relations between the United States and Japan were severed when both nations declared war on each other in the wake of Japan’s 1941 attack on Pearl Harbor, Hawaii. After years of fighting in the Pacific region, Japan signed an instrument of surrender in 1945. Normal diplomatic relations were reestablished in 1952, when the Supreme Commander for the Allied Powers, which had overseen the postwar Allied occupation of Japan, disbanded. The first Treaty of Mutual Cooperation and Security between the United States and Japan was signed in 1952. Relations between the two allies have been strong ever since.

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