Tension is mounting in Northeast Asia as the U.S. flew two nuclear-capable B-52 bombers through what China has recently designated as an air defense zone, apparently to protest the unilateral demarcation.

Taking off from their home base of Guam, the unarmed strategic bombers on Tuesday flew through China’s air defense identification zone without prior notice and returned to base.

Washington officials cast the deployment simply as part of the long-planned training mission. But analysts say it was an apparent show of force against Beijing’s unilateral pursuit of interests in aerial and maritime domains.

America’s major concern as to China’s increasing assertiveness is that based on its growing military might, the ascendant power would attempt to alter the norms and “rule-based” order that have maintained the status quo.

In particular, Washington has voiced its worries that Beijing, with its aggressive military strategy, could undermine the protection of “global commons” such as unfettered freedom of navigation and commerce in the region where vital sea lanes of communication converge.

“This announcement (of the air defense zone) from the Chinese government was unnecessarily inflammatory,” White House deputy spokesman Josh Earnest told reporters.

“There are regional disputes in that part of the world and those disputes should be resolved diplomatically.”

China’s demarcation of the air zone, announced last Saturday, appeared designed to back up its claim to the East China Sea island chain called Senkaku in Japan and Diaoyu in China.

But the dispute is apparently escalating into major-power strong-arming with the U.S., which has explicitly supported Japan’s administrative control of the islands that are in a strategically crucial point for China to project its power further into the Pacific.

“The current dispute concerns China’s push for territorial integrity. And at the same time, it is Beijing’s response to the moves by the U.S. and Japan to strengthen its alliance (to keep China in check),” said Kim Tae-hyung, professor in the department of politics and diplomacy at Soongsil University.

“Sending the strategic bombers at this juncture carries some military nuance beyond what they call a training mission. Some period of heightened tensions between the U.S. and China seems to be inevitable for the time being.”

China’s recently declared air zone incorporates key points that Beijing has long sought to break through to expand its sphere of influence.

The air zone covers areas over part of what analysts call “the first island chain” ― a string of archipelagos in the East Asia that links the Japanese archipelago, Ryukyu islands, Taiwan and the northern Philippines.

Under its long-term maritime strategy based on its growing naval clout, Beijing seeks to project power far beyond the “second island chain” linking Guam and Indonesia, and all the way into the “third island chain” ― waters near Hawaii.

Apparently to keep China in check and maintain its regional preponderance, Washington has, in recent years, employed a “rebalancing” policy toward the Asia-Pacific.

The policy seeks to engage its allies and partners to strengthen security cooperation, its leadership in multilateral institutions and its military presence in the region. The U.S. plans to bring 60 percent of its naval fleets into the region by 2020.

Japan’s strong reaction to China’s push for expanded maritime interests has further escalated regional military tensions. Tokyo, seeking heavier armament, said it would not accept China’s air demarcation.

“I am strongly concerned as it is a profoundly dangerous act that may cause unintended consequences,” Japan’s Prime Minister Shinzo Abe told parliament.

Despite increasing tensions, experts say the U.S. and China might try to avoid any critical confrontation given their deepening economic interdependence, international conflict-management mechanisms and dozens of bilateral dialogue channels.

They also noted a plethora of domestic issues facing Washington and Beijing would, after all, prevent them from taking aggressive military approaches to address their conflicts.

The U.S. currently struggles with financial constraints and broader health care legislation, which China is grappling with income disparities, regional gaps between inland and coastal areas, political reform and corruption.

But Chinese history shows domestic conundrums including political upheavals did not always constrain the country’s military moves.

China fought against the U.S. during the Korean War in the early 1950s when it was struggling just a year after its national foundation in 1949. In 1962, China also went to war against India when it was reeling from the Great Leap Forward (a botched campaign to industrialize and collectivize China’s economy).

In 1969, China also engaged in an armed border conflict with the former Soviet Union despite extreme ideological division amid the Cultural Revolution.

By Song Sang-ho (sshluck@heraldcorp.com)