Commitment without Control: The Burdensharing Dilemma in the US-Japan Alliance

Since the early Cold War, the United States has maintained a system of extended deterrence around the world. Its centerpiece, in contradistinction to other eras of great power politics, has been the physical garrisoning of allied territory. To deter would-be aggressors, Americans have demonstrated with this ‘tripwire’ strategy that they could not possibly avoid involvement. Even so, Washington has often recognized the costs of such a total commitment for intra-alliance management. When an adversary knows the United States is automatically committed, so does the security partner. Although America may not want war and its enemy may be deterred, an ally’s actions may still spark conflict in a phenomenon known as ‘entrapment.’I argue in the following chapters that in the postwar era, Americans have confronted a ‘burdensharing dilemma.’ There is risk to an ally having the capacity for independent military action. On the one hand, the demands of collective defense against American or mutual adversaries incentivize policymakers towards the growth of allied military power. In a myriad of ways, US officials have hoped countries like South Korea, Japan, and West Germany would share more of common burden in both cold and hot wars. Yet on the other hand, America has feared cases of ‘tactical entrapment’ and ‘strategic entrapment,’ whereby an ally’s autonomous capacity is used to cause war or destabilize a security environment such that war becomes more likely. When Washington enters into an extended deterrence that includes a tripwire, there are strong geopolitical reasons to suppress that ally’s ability to defend itself. Otherwise, in the analogy most beloved by International Relations (IR) scholars, an open-ended commitment would be like sitting in the passenger seat in a game of chicken.By establishing mechanisms of control such as consultation, the discouragement of specific types of rearmament, and the removal of allied decisionmaking power over the activity of their own armed forces, Americans have tried to grab both horns of the burdensharing dilemma and overcome it. To some extent, they have been successful. But the burdensharing dilemma has not gone away. Its tradeoffs and dangers, whether recognized or not, continue to plague US alliance management in the Rebalance to Asia much as they did in the Cold War.