The shift in the government’s foreign policy stance was subtle but clear: Japan was reorienting itself toward Asia and away from the United States. Difficulties over the Futenma base issue compounded the view of a troubled and tense bilateral relationship and a possible weakening of alliance commitments on both sides. Some in the DPJ, such as former leader Ozawa Ichiro, made explicit their antipathy towards the presence of US military forces in Japan.

The Sino-Japanese dispute over the Senkaku Islands has changed all that. It has energised the Japan-US alliance across a number of fronts.

First, the United States has offered reassurance to Japan that the Senkaku Islands fall within the scope of the Japan-US Security Treaty, which obligates the United States to defend Japan. The Japanese press reported an explicit commitment from Secretary of State Hillary Clinton in talks with Foreign Minister Maehara Seiji in New York in September. Chairman of the Joint Chiefs of Staff Mike Mullen and Secretary of Defense Robert Gates have also expressed strong support for Japan, offering assurance that the US will fulfil its alliance responsibilities. These statements underline the deterrence function of the alliance, which is the chief rationale for US bases in Okinawa. The Senkaku ‘shock’ will, therefore, become a factor in the mix of considerations determining the resolution of the Futenma base issue.

Second, the US side is leveraging the deterioration in Japan’s security environment to apply pressure on the Japanese government to maintain, if not increase, the fiscal allocation for ‘Host Nation Support’ for US forces in Japan, which the Japanese call the ‘sympathy budget’, or omoiyari yosan. While these payments were under review to assist in budget cuts, there are indications that the funds will continue at least at the current level. This can be directly attributed to the newfound importance that the government is attaching to the alliance after the recent dispute with China.

Third, Foreign Minister Maehara Seiji, who is well known for his pro-US sympathies and who in the past has referred to a China ‘threat’, has proposed a review of the 1997 Japan-US Defence Cooperation Guidelines, which enable Japan to provide logistical and rear-area support for the United States in the event of regional conflict. Such a development could conceivably see an expansion in Japan’s operational role and thus the operational capability of the alliance. There may also be developments in other areas of Japanese security policy such as the ban on exporting weapons and related technology, and participating in collective defence. Both Defence Minister Kitazawa Toshimi and Foreign Minister Maehara are in favour of reviewing the weapons export ban in order to strengthen the alliance, a move that is strongly supported by US Defense Secretary Gates.

Fourth, in addition to a joint SDF-USFJ exercise to reclaim a remote southwestern island in December, a joint command post exercise (CPX) will be held next January, which incorporates the defence of southwestern islands for the first time. The CPX will entail Japanese and US forces establishing a south-western barrier to bottle up Chinese naval forces in the East China Sea, simulating the deployment of military forces to one of the Amami Islands and other outlying islands, and operations to recapture islands from foreign forces.

The Southwest (Nansei) or Ryukyu Islands have a special value in solidifying the alliance because they are an issue on which US and Japanese strategic interests are strongly aligned. These islands are not only central to Japan’s sovereign territorial interests but are also highly relevant to US naval strategy in the region.

James Holmes and Toshi Yoshihara of the Jamestown Foundation argue that if China gained possession of one or more of the islands in the Ryukyus, it would secure vital straits through which a Chinese PLAN flotilla could exit from the East China Sea into the Western Pacific as well as protecting PLAN shipping through the straits. Further, a Chinese island campaign would underpin what the US Department of Defense has called China’s anti-access/area denial (A2/AD) operations against the US navy. This strategy is designed to prevent US naval reinforcements from reaching maritime Asia as well as blocking in-theatre forces from entering the Taiwan Strait and the seas off the east coast of Taiwan. Holmes and Yoshihara give the Senkakus, which lie due north of the southwestern tip of the Ryukyus, potential significance in this strategy as political, psychological and resource assets.

Funabashi Yoichi concurs and reports the words of a US administration official who stated: ‘I think about what will happen to the Senkaku Islands if the marine corps leave Okinawa. A Chinese flag will probably be standing on the Senkaku Islands the next day.’ Funabashi interpreted this comment as an American attempt to play the ‘Senkaku Islands card’. As it turns out, the need for such a ploy has been obviated by China itself.

Indeed, in a conflict scenario where the Chinese capture one or more of the Ryukyu Islands, the marines based in Okinawa could possibly play a key role. Andrew Krepinevich, President of the US Center for Strategic and Budgetary Assessments was quoted in the Asahi Shimbun on 5th May as saying that ‘the marine corps stationed in Okinawa could play a role in territorial disputes in the South China Sea etc’ (i.e. presumably also in the East China Sea).

The overall outcome of the Senkaku Islands dispute has been a Japan-US gain and a Chinese loss. The alliance is more highly valued in the region, particularly by other countries embroiled in their own maritime territorial disputes with China. The dispute also offers the Obama administration a chance to rebuild the bilateral security relationship by recruiting Japan into a strategic coalition against China. Meanwhile, the Kan administration has been handed a powerful argument in favour of maintaining a strong marine presence in Okinawa. Across a spectrum of bilateral issues including island defence, the Senkaku ‘shock’ has turned out to be a ‘Senkaku tailwind’.

Aurelia George Mulgan is Professor of Politics at the University of New South Wales, Australian Defence Force Academy.