In a recent contribution to The Strategist, Rod Lyon argues ^[1] convincingly that Australia needs to engage its US ally over the future credibility of its nuclear extended deterrence posture in Asia. It doesn’t stop there. Indeed, the current stand-off between China and Japan over the Senkaku/Diaoyu islands is a timely reminder that US conventional extended deterrence also needs refinement, particularly in East Asia.

Traditionally, US conventional deterrence for its East Asian allies has relied on ‘direct defence’, i.e. deterrence by denial through the unmatched ability to defeat any conventional attack against its forward deployed forces and/or allied territory. Up to now that’s been a credible strategy. But today China has embarked on a long-term trajectory to contest US naval supremacy in the ‘first island chain’, which includes Taiwan and parts of the seas surrounding Japan. While the People’s Liberation Army (PLA) still has lots of catching up to do, the gap is slowly closing. Already, American fixed targets (bases) in Japan and South Korea are in striking range of China’s growing missile arsenals. The PLA is also developing systems to pose a threat to high-value moving targets (US carrier strike groups). The aim is to make it too costly for the United States to intervene in a future regional crisis between China and its neighbours.

This development has important ramifications for the American deterrent posture. By raising the stakes, China makes it hard for the United States to militarily coerce it in a future regional crisis unless major strategic interests are at stake. Consequently, the Pentagon seems to putting a stronger emphasis on deterrence by punishment, which relies on distant strike-capabilities and putting a greater portion of its forces out of the PLA’s missile range. In addition, recent US force posture reports stress the need for Japan and South Korea to invest more in their own denial capabilities. And a growing number of US commentators argue that America’s ability to defend its ‘de facto’ ally Taiwan might become too costly ^[2] (PDF) as its interests are merely associated with ‘reputational risk’; notwithstanding good reasons why Taiwan also matters geostrategically to the US and its allies.

However, this invokes a classical alliance dilemma of ‘abandonment’ and ‘entrapment’. A vague commitment to defend its East Asian allies in a conflict of lesser interest to Washington not only contributes to fears of abandonment on the part of allies, it might also encourage Chinese risk-taking. A strong commitment, however, might increase allies’ risk-taking during crisis and raises the spectre of ‘entrapment’ in an unwanted conflict with China. The crisis over the Senkaku islands is a case in point. Washington has urged both parties to exercise restraint, knowing that Tokyo would expect it to come to its defence should the conflict spiral out of control. Failure to do so would deal a mortal blow to American credibility and could lead to even greater cycles of armament in the region. Yet, the Japanese government seems ambivalent about US commitment ^[3]; it is unsure of what exactly the US would be willing to bring to the fight.

Any move to provide China with greater strategic breathing space as its power grows thus raises critical questions about US extended deterrence relationships with its allies: how can deterrence by punishment be credible in territorial conflicts which are vital for allies but not for the US, particularly if it involves the risk of nuclear escalation with China? What will be the ‘tripwire’ for US military engagement in such regional conflicts between China and its allies? Or will there come a time when the US will signal to its allies and partners that they are essentially on their own when it comes to certain disputes with China?

Deterrence depends significantly on capability and credible communication to both allies and adversaries. In East Asia, the US needs a balanced mix of both ‘denial’ and ‘punishment’ capabilities. Greater investments in long-range strike have to be combined with increased efforts to strengthen direct defence of forward deployed troops and allied territory. More needs to be done to assist Taiwan’s capacity to withstand a PLA opening attack. Greater cooperation with Japan to harden bases and to further strengthening ballistic missile defence is a welcome sign.

Second, and probably much more important, is communication. Obama’s ‘pivot’ announcement was a good start but it is not a strategy that sets out how the United States aims to ‘shape’ Chinese and allied behaviour, including through extended deterrence. It’s odd that the last US East Asia Strategy Report dates back to 1998. Uncertainty also surrounds the ‘AirSea Battle’ operational concept, which has allies wondering if it is more about reducing US footprint in the region than reassuring them. Just as in Western Europe during the Cold War, the United States should clearly communicate its willingness to put forward deployed forces in East Asia in harm’s way. No serious Chinese planner could assume that an attack on US forward deployed forces, fixed or moving, would be left unanswered. Finally, the US needs to clarify whether the defence of Taiwan or territorial dispute between its allies and China are really only of reputational interest. Ambiguity is not only counterproductive to crisis stability since it could invite Chinese miscalculations about America’s intentions and will to fight, it also puts into question the fundamental principle of solidarity on which any alliance rests.

This matters to Australia for at least three reasons. First, Australia’s prosperity is critically dependent on peace and stability in East Asia. Second, over time the same deterrence dilemma will also affect US alliances and security partnership in Southeast Asia, a region much closer to home. And thirdly, American shifts in deterrent posture have direct implications for Australia, which will be discussed in part II.

Benjamin Schreer is deputy head of the Strategic and Defence Studies Centre at the Australian National University.