WASHINGTON (AP) -- Islamic extremists grab parts of Iraq and Syria. Yemen slides into civil war. Iran's nuclear program strains U.S. relations with Israel. Ukraine fights Russian-backed separatists.
At a time of crisis across the Middle East and beyond, the Obama administration is trying to keep its focus on a widely advertised shift to Asia.
The administration has pursued the strategy since 2011, arguing that no region is more important to the United States' long-term interests, particularly as the rise of China brings concern in other Asian capitals.
Defense Secretary Ash Carter will visit Japan and South Korea this week, part of a series of planned trips to the region during his first year as Pentagon chief. He will visit India and attend an international security conference in Singapore in May, and he may visit China later in the year.
Before he became defense secretary in February, Carter was a supporter of what the Obama administration calls its "rebalance" to Asia. That term meant to rebut the implication that by giving more attention to Asia, Washington is pivoting away from its traditional allies in Europe and its extensive commitments in the Mideast.
While serving as the deputy secretary of defense, Carter said in May 2013 that international terrorism, persistent Mideast turmoil, nuclear proliferation and cyberthreats would continue to require Pentagon attention.
"We also see great opportunities: Among them, to shift the great weight of the Department of Defense, both intellectual and physical, that has been devoted to Iraq and Afghanistan, to the Asia-Pacific region, where America will continue to play its seven-decade-old pivotal stabilizing role into the future," Carter said then.
His Tokyo visit beginning Tuesday is meant in part to smooth the way for Japanese Prime Minister Shinzo Abe's visit to Washington in late April. That trip will coincide with a historic reworking of the guidelines that govern U.S.-Japan defense cooperation in a way intended to give Japan's self-defense forces a more active role in Asian security.
Japan's post-World War II constitution limits the country's use of force, but Abe last year approved a reinterpretation of the constitution, and his government has proposed legislation to enable defense changes.
A strategic goal shared by Tokyo and Washington is for Japan to participate in what is known as collective self-defense, meaning that it could come to the aid of an ally under attack even if that did not entail a direct attack on Japan or its own military.
Carter plans to cap his week in Asia with meetings with South Korean government officials in Seoul and visit U.S. troops.
Among the hottest defense topics in South Korea is the prospect of deploying an advanced U.S. missile defense system, called the Theater High Altitude Area Defense, or THAAD. The U.S. is thought to want to place the weapon system in South Korea as a defense against North Korean ballistic missiles, but Seoul has balked, in part out of concern that China opposes the move.
U.S. relations with Japan and South Korea are strong, but the alliances are sometimes tested by differing views on how to handle North Korea's periodic provocations and China's rapid military modernization.
A new assessment of the outlook for Asian security, released Thursday by the Carnegie Endowment for International Peace, argues that although Asian "hot wars" cannot be ruled out, a continuation of the status quo is a more likely scenario over the next five to 25 years. This would likely mean a mix of economic cooperation and intensifying military competition and rivalry.
The assessment was requested by the Pentagon and is part of a larger study sponsored by the U.S. Pacific Command.
"Allies remain concerned about the sustainability of U.S. predominance in the region," the study said. "Many assume the United States will not retain its predominance -- or that it already is lost -- and expect increased U.S. demands on allies for important security functions."
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