This week’s AUSMIN talks in Sydney, involving the U.S. secretary of state and secretary of defense and their Australian ministerial counterparts, have reaffirmed the Australia-U.S. alliance as a cornerstone of security in Indo-Pacific Asia. Understandably, Canberra has a deep reliance on its relationship with Washington, just as Tokyo and other U.S. allies do on theirs.

Yet in a changing Asia, not even steadfast allies like Australia can afford to put all their eggs in the alliance basket. Thus in a new research paper, we argued that it is time for new and creative ways to deal with Asia’s strategic uncertainties: the creation of “middle-power coalitions,” new security arrangements that include neither China, nor the United States. This is not a replacement for partnership with America or efforts to engage with China, but a complement to both approaches.

Along with Australia, a country well placed to start this process is India. Before flying to Sydney, Defense Secretary Hagel was in New Delhi for a high-level security dialogue with India’s new Modi government. His distinctly Indo-Pacific itinerary reflects the growing importance of India and Australia as players in Asia’s emerging strategic dynamic.

The following illustrates a defining part of that dynamic: A rising China’s assertiveness and uncertainties about America’s response (Hagel’s travels notwithstanding) are causing many countries in the region to look beyond traditional approaches to security—not only U.S. alliances, but also nonalignment and multilateral institutions like ASEAN.

Bouts of coercive behavior against Vietnam, the Philippines and Japan have alarmed the security establishments in many countries, making them ponder whether this is the template for how a powerful China will more generally behave. Meanwhile relations between China and the United States have been on a troubled trajectory. Moments of cooperation, like China’s recent involvement in multination naval exercises off Hawaii, cannot mask mistrust—China sent an extra ship to spy on the same exercise.

At the same time, there are likely to be lingering concerns in many regional capitals about American attention and resolve. These arise from perceptions of a U.S. policy establishment divided on questions both about coping with Beijing’s rise, and about U.S. global leadership more generally. Despite Washington’s assurances, many Asian nations worry about the constancy of American purpose in Asia. For example, the Obama administration has moved from seeking a degree of accommodation with China to announcing a high-profile pivot to Asia and then a seeming de-emphasis of the rebalance strategy—all in the past six years.

Asians also worry about the combination of America’s continuing preoccupation with the Middle East, the breakdown of post–Cold War understandings with Russia, hints of renewed isolationism and an increasingly dysfunctional domestic polity in Washington. All of this will make the United States a less predictable variable in the Asian power calculus.

Many governments in the region weigh the risks of U.S.-Chinese confrontation and conflict. But they must also be pondering a very different long-run scenario, an American accommodation of China that subordinates the interests of the many countries in between.

In theory, it would seem normal and acceptable for a rising power’s interests to be accommodated. The realities of the current Indo-Pacific strategic situation, however, mean that an effort at accommodation would bring major risks and uncertainties: accommodation would itself be destabilizing. Any form of accommodation between the dominant power, the United States, and the rising challenger, China, would involve Washington’s ceding additional space and role for Beijing in the management of the regional order. This would have been welcome if Beijing’s neighbors were politically comfortable with China’s rise. Today they are not. For those in Asia with significant concerns about how Beijing might use its growing power, American support or legitimization of a larger Chinese role would create strategic anxieties.

It is difficult to imagine a large and workable Chinese sphere of influence in Asia that does not challenge the interests, security and dignity of other substantial countries, such as Japan, India or Vietnam, and is not accordingly resisted by them. To concede control of the South China Sea as part of a Chinese sphere of influence would be to concede, as prominent pro-accommodation scholar Hugh White has acknowledged, “more than is compatible with the vital interests of other great powers.” Moreover, a withdrawal to an “offshore balancing” strategy would not be cause for comfort. If the United States is already cautious about making shows of force against coercion in an Asia where it maintains strategic presence, it is difficult to envisage it returning forcefully to the region in all but a catastrophic scenario—at which point it could well find itself lacking the capability advantages, such as in maritime surveillance, that only “being there” can provide.

In all this, although the U.S.-Chinese dynamic will clearly be the bilateral relationship that will most shape or shake the region, it is a grave mistake for the countries in between to see themselves as powerless. These can be called variously “the powers in the middle,” “the middle players,” even “the middle powers.” These days, the idea of middle-power diplomacy is relevant not only to the global multilateral activism of the likes of Australia and Canada. It can and should be applied to many countries in Indo-Pacific Asia. It makes sense to understand a whole range of significant countries as middle powers: ranging from Australia, South Korea and the more militarily and diplomatically capable Southeast Asian countries—Indonesia, Vietnam, Malaysia, Singapore—through to Japan and India. The latter two, despite some obvious major-power attributes, can plausibly be defined as middle powers for the time being, given their internal challenges and the limits of their capacities to shape the strategic environment unilaterally.

The key point is that by working together, Asia’s middle powers have a prospect of affecting the regional balance of power. They have their own kind of strength in numbers. For instance, as of 2013, four of the region’s middle powers—Japan, India, Indonesia and Australia—had a combined population of 1.64 billion, a combined GDP of US$ 9.13 trillion and combined defense expenditure of US$ 127.8 billion. By contrast, the United States has a population of 316.5 million, a GDP of US$ 16.78 trillion and defense spending of US$ 640.21 billion. For its part, China's population was 1.36 billion, its GDP was US$ 9.18 trillion and its defense budget was US$ 188.46 billion. The challenge, of course, is to coordinate their capacities better.

That has begun. Amid these times of strategic uncertainty, it should be no surprise that India, Japan, Australia and several substantial Southeast Asian countries are quietly expanding security cooperation with each other, as well as with the United States. But this has been tentative and the time has come for a step change. Thus in our new research paper, we propose the creation of “middle-power coalitions”: informal arrangements where regional players cooperate with one another on strategic issues, working in self-selecting groups that do not include China or the United States.

Areas of cooperation could include security dialogues, intelligence exchanges, military capacity building, technology sharing, agenda setting for regional forums and coordinated diplomatic initiatives to influence both American and Chinese strategic calculations. These ambitions are more realistic than they may seem at first blush. Many countries, including India, Japan, Australia, Vietnam and Indonesia, are already improving their bilateral efforts in many of these areas, and some would likely be receptive to proposals for trilateral dialogues or other new arrangements.

A set of overlapping, flexible coalitions based on interests, capabilities and willingness to contribute would build regional resilience against the vagaries of U.S.-Chinese relations, including against the extremes either of conflict or collusion.

This new kind of regional self-help would also reinforce the multipolar quality of the emerging Indo-Pacific order, encouraging continued U.S. engagement without unduly provoking China. It would prudent mutual assistance among regional nations and thus could hardly be dismissed as U.S.-led “containment.” It would also counter China’s recent stratagem of a supposed “Asia for the Asians” approach to security cooperation, typified by Beijing’s efforts to elevate the previously little-known Conference on Interaction and Confidence-Building in Asia—even though that forum does not include Japan, Indonesia or the Philippines, among others, as full members.

How to begin? It would make sense to leverage existing bilateral partnerships, and one promising option would be to build upon the promising strategic ties between Australia and India. These two countries may seem an unlikely couple: two democracies very different in economic development, population and diplomatic traditions. Yet Delhi and Canberra have drawn much closer together over the past decade. Historical mistrust over nuclear matters has been surmounted, while their strategic interests have converged around issues like maritime security, counterterrorism and a regional order not dominated by any one power.

Australia and India have their own substantial capabilities, the benefits of their strategic geography close to vital sea-lanes, and most importantly, the potential to engage and mobilize a wide range of partners between them: a mix of U.S. allies and notionally nonaligned states. With Australian Prime Minister Tony Abbott reportedly due to visit India at the start of September, and India’s dynamic new prime minister, Narendra Modi, expected to visit Australia in November, India and Australia are well-placed to form the core of this “middle-power coalition” building.