Executive Summary

What is the optimal posture of U.S. and allied military forces throughout the Indo-Pacific to deter Chinese military adventurism and, if necessary, win a regional war? The United States has begun to rethink its military footprint in the region in response to China’s increasing strike capabilities. At the same time, U.S. allies whose support is crucial for U.S. force posture—the Republic of Korea, Japan, the Philippines, and Australia—are upgrading security cooperation with each other in ways that have effects similar to force posture initiatives.

This Asan Report examines how this evolving patchwork of U.S. and allied force posture initiatives can become more integrated, resilient, and sustainable. The report argues that the debate about allied force posture in the Indo-Pacific should be expanded beyond just deployments of uniformed military forces in each other’s territories. Chapter one discusses how the United States is rethinking its military presence in the Indo-Pacific to be more flexible and distributed, yet why it has struggled to make significant changes to its force posture.

Chapter two examines the different responses by allies to possible changes in U.S. force posture. Despite hosting different U.S. forces in terms of size, composition, and permanence, none of them appear willing to see the U.S. military posture radically changed in either their own situation or that of other allies, especially if that means trading places with another ally.

Chapter three shows how allies and partners are pursuing their own, more eclectic, types of force posture arrangements throughout the region with each other, including new security treaties, rotational forward deployments, reciprocal access agreements, cross-national defense industrial facilities, and land leasing arrangements. These are designed to be flexible, rotational, and have a light military footprint on local communities. It finds that the ROK has been notably absent from these quasi-force posture initiatives.

Chapter four presents new force posture models that play to the strengths of allies, with a focus on preserving a social license to operate foreign military and defense industrial access. The first model is what it calls the “coalition lily pad” strategy of using access arrangements to lay the foundations for coalition operations with a light military footprint. The second model is what it calls the “military-industrial force nexus” of leveraging overseas defense industrial presence as a form of hybrid force posture. Both of these strategies would be more politically feasible to encourage allies, especially the ROK, to expand their military and defense-related footprint in the region.

Chapter five offers policy recommendations to improve U.S. and allied force posture in a coalition framework.

1. U.S. posture decisions with one ally can have significant implications for other allies, so the United States should establish collective forums for consultations to gather allied perspectives.

2. The ROK should initiate reciprocal access agreement negotiations with other U.S. allies to avoid being excluded from the emerging coalition network.

3. The ROK should consider limited regional force deployments focused on capacity-building as part of the growing regional role of the ROK-U.S. alliance.

4. The ROK should explore the posture implications of its defense industrial partnerships and facilities and how they can support coalition deterrence.

5. Allies and partners should coordinate their local community engagement around potential wartime access points by investing in appropriate social license contributions.

6. Other partners—such as those from Europe—should initiate consultations on how their territories in the Indo-Pacific could facilitate coalition lily pads or the military-industrial force nexus.

Table of Contents

Executive Summary

국문 요약본

Introduction

I. U.S. Force Posture in the Indo-Pacific

1. The Trump Administration and Force Posture Burdens

II. Allied Reactions to Changing U.S. Force Posture

1. South Korea: Fears of “Strategic Flexibility”

2. Australia: Consolidating Its Role as a “Pivotal Strategic Node”

3. Japan: Embracing Entanglement

4. Philippines: Horizontal Escalation

5. Conclusion

III. Quasi-Force Posture Initiatives by Allies

1. Australia: Defending Northern Approaches

2. Japan: Conditional Reciprocal Access

3. Philippines: Welcoming Capacity Builders

4. European Partners: Territories and Forward Presence

5. South Korea: In Search of a Rationale?

6. Conclusion

IV. New Models of Allied Force Posture

1. Social License for Force Posture

2. The Coalition Lily Pad Strategy

3. The Military-Industrial Force Nexus

V. Policy Recommendations

1. For the United States

2. For the ROK

3. For Allies and Partners

Conclusion