Concerns have been expressed by former US secretary of state Henry Kissinger and former US national security adviser Zbigniew Brzezinski. They echo the lexicon of the Cold War when writing in recent editions of Foreign Affairs. Kissinger notes the importance of not seeking to confront or contain China. He does not see China's military build-up as an exceptional problem and emphasises China's internal troubles. He argues that the challenge for the two nations is to move to a genuine effort at co-operation rather than an assumption of confrontation.

Brzezinski refers to an anxious US and an overconfident China. He suggests that the US needs to provide room for China. This includes reducing close military reconnaissance against China, explaining the ambiguity of US policy on Taiwan and developing rules for naval operations.

Australia makes a "middle-power" contribution to the diplomatic and economic decisions shaping the future of the Asia-Pacific. Australia's military is capable but carries limited influence in this big league. The Australian Defence Force is crucially dependent on US support to conduct high-intensity operations and in lesser conflicts would be hindered without access to US intelligence, ammunition, logistic and transport support.

The US is the play-maker in security deliberations in the Asia-Pacific. It is an overwhelming force, including among its allies. It is difficult to say no, even as a friend. This limits Australia's ability to make independent decisions. If too closely aligned with the US, Australia will be associated with any mistakes. US actions, mounted from Australia, will implicate Australia. In the Cold War US joint intelligence facilities were a target for Soviet nuclear weapons.

Recent US force posture redeployments are primarily about control of the sea lines of communication in the Pacific and Indian oceans. Also prominent are the disputed fishery and resource assets of the South China Sea and China's growing ability to deny naval and air access to its coast. The key players in this environment are the US Navy and US Air Force operating under evolving Air-Sea Battle doctrine. Future Australian agreements with the US will no doubt involve greater access for air and naval forces to ports, training areas, mounting bases, and repair and sustainment facilities in and across Australia.

These are momentous decisions with far-reaching consequences. They potentially implicate Australia in a series of actions that could lead to increased tension and even conflict with China. War is improbable but not impossible. The Australian defence white paper of 2009 advocated a strategic posture that hedged against the growth of China. These agreements take that process a step further. Australia needs to be careful that it does not make inevitable the future that it should fear the most. Current decisions are being made without public debate or discussion. Once made they will be difficult to reverse.

The deployments have already attracted negative attention. Indonesia has questioned the arrival of the marines. Chinese academic Liao Kai, writing in the US Air Force's influential Air & Space Power Journal, warns that Australia should keep its military co-operation within an appropriate scope. There have also been proposals that the Chinese trade relationship with Australia should be downgraded.

So far Indonesia and China have accepted the explanation that the deployments will result in an improved capability for disaster and humanitarian missions. As US forces build up, this will be harder to believe. The US pivot to the Asia-Pacific has substance and the US is likely to persist. Australia needs to consider if, where and when to draw the line.