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President Obama traveled early Thursday to the Australian city of Darwin, a base for past U.S.-Australian military cooperation. Now it will be one of several military bases from which the U.S. operates as it seeks to reassert itself in Asia.
Some 250 U.S. Marines will arrive in northern Australia next year, a number that will later expand to about 2,500. U.S. jets and warships will also train with the Australians.
Abraham Denmark, a China specialist at the Center for Naval Analyses, sees the new focus on Asia as a natural evolution of U.S. interests.
"It has half of the world's population, three of the world's largest economies, it represents one-third of world trade and it has several of the world's largest militaries, including some potential adversaries," Denmark says. "So it's very important for the United States to be there."
The decision to increase military cooperation with Australia has been in the works for several years. It's part of a broader strategy calling for more diplomatic and economic cooperation with the region, a repositioning of U.S. troops based in North Asia, and a downgrade of forces in Iraq and Afghanistan.
Patrick Cronin, a senior Asian analyst with the Center for a New American Security, says placing military assets in Australia was also a response to concerns by U.S. allies in Asia.
"The region was watching the United States over this last decade get deeper and deeper into this so-called war on terrorism and involved in counter-insurgencies and said, 'Don't you understand that this region is changing daily?'" Cronin says. "China's military modernization is affecting everybody's calculations."
The buildup of China's modern military forces has been paid for by its economic success. Denmark, with the Center for Naval Analyses, says China has the right to invest in its military, but its neighbors — and the U.S. — have grown concerned about Chinese efforts to deny access to critical commercial waterways.
Denmark says the South China Sea has become a "focal point."
"In recent years, China has acted very assertively in the South China Sea and started harassing American ships and other country's ships," he says.
'It Is Just Prudent'
The announcement about increased military cooperation with Australia comes the same week as the U.S. and other Asian nations negotiate a new free-trade deal, which for now does not include China. That, along with a push to renew ties with Asian allies, has raised questions whether the U.S. is trying to "contain" China.
Geoffrey Garrett, the head of the United States Study Center at the University of Sydney, says that isn't the case. He says there's a belief that China's rise will continue to be benign.
But, Garrett says, "it is just prudent for us to ensure against the small possibility that China's rise will turn from being benign to being more malign."
Cronin, with CNAS, says the decision to base Marines in Australia will help reassure allies that the U.S. is going to be a long-term and important player in Asia. He says it's possible there will be similar agreements with other Asian nations in the future, noting a plan for the U.S. to station two small combat ships in Singapore.
"That could be replicated elsewhere and people are thinking about the Philippines, people are thinking what could be done with Vietnam," he says. "Those kinds of cooperative arrangements are much more likely to be 'red lines' with China than anything the U.S. does with Australia."
Yet a Chinese spokesman expressed concern, saying the newly sealed military agreement between the U.S. and Australia "might not be appropriate and deserved greater scrutiny."