China’s rapidly improving military capability and its increasingly aggressive effort to keep U.S. military forces out of striking range are raising concerns about America’s future ability to protect its vital interest and its allies in Northeast Asia.

Beijing’s expanding and modernizing navy, air, and missile forces, the recent revelations of an apparently operational anti-ship ballistic missile, and the first flight of what could be a fifth-generation, stealthy fighter are part of China’s attempt to create what is known as an anti-access, area-denial (A2/AD) shield. Those advanced combat systems, combined with improving intelligence, surveillance, and reconnaissance (ISR) capabilities, are intended to nullify America’s superior naval and air power and make it unacceptably dangerous to attempt to project military power into China’s expanding zone of influence.

The threat was highlighted in a comprehensive 2010 report by the Center for Strategic and Budgetary Assessments (CSBA), a highly regarded Washington think tank, which warned that China’s “ongoing efforts to field robust A2/AD capabilities are threatening to make U.S. power projection increasingly risky and, in some cases and contexts, prohibitively costly.”

“If this occurs, the United States will find itself effectively locked out of a region that has been declared a vital security interest” for 60 years, and it also would “leave longstanding U.S. allies and partners vulnerable to aggression, or more likely, subtle forms of coercion,” the CSBA report stated.

To counter that threat, Gen. Norton Schwartz, the Air Force chief of staff, and Adm. Gary Roughead, the chief of naval operations (CNO), directed their staffs to develop the AirSea Battle Concept as a guide to better coordinate and integrate their combat systems and doctrines to overcome the A2/AD barrier.

But independent defense analysts, including CSBA, argue that an effective counter to the A2/AD threat requires investments in a range of expensive systems and programs that the two services have neglected in the past.

And, with the growing political focus on the soaring national debt putting intense downward pressure on the defense budget, there are serious questions as to whether the funding necessary to put real muscle into AirSea Battle will be available.

The CSBA document, which basically echoes Pentagon thinking, warns that, in a conflict, China would be expected to launch preemptive attacks against U.S. forces based or operating in the Western Pacific, seek to keep U.S. air and naval forces well out of striking range, disrupt their command and control networks, and heavily constrain operational logistics.

“If this occurs, the United States will find itself effectively locked out of a region that has been declared a vital security interest” for 60 years, and it also would “leave longstanding U.S. allies and partners vulnerable to aggression, or more likely, subtle forms of coercion,” the CSBA report stated.

China’s goal would be to inflict substantial losses on U.S. forces quickly, thereby lengthening their operational timelines and nullifying the space and digital assets on which U.S. forces heavily depend for long-distance, high-volume communication, ISR, and precision-guided munitions.

China’s ability to execute its A2/AD strategy is being enabled by a vast increase in its defense spending fueled by its soaring economy. The Pentagon estimates Beijing’s military spending jumped from a reported $17 billion in 2001 to at least $150 billion in 2009.

That has paid for a rapid modernization of the People’s Liberation Army (PLA) and Air Force (PLAAF) and a transition of the navy from a small, outdated coastal defense force to a sizable modern fleet with increasing “blue water” capabilities. That fleet includes at least 62 submarines, with more being added annually, the Office of Naval Intelligence reported.