Michael Wesley is an adjunct professor at the University of Sydney and a nonresident senior fellow at the Brookings Institution.

A central theme in the Obama administration’s recent foreign-policy narrative has been that the United States is returning to Asia after a decade of distractions in the Middle East. It is easy to argue that Asia should be America’s highest foreign-policy priority. After the financial crisis, Asia emerged as the growth dynamo on which the hopes for the revival of the American and global economies are pinned. At the same time, this very economic dynamism produces huge bilateral trade deficits and is largely responsible for the steady decline of American manufacturing. And Asia is home to the United States’ most serious strategic competitor: China.

America is about to discover that Asia has changed dramatically over the past decade. Its main strategic competitor is now its largest creditor; its most important regional ally, Japan, has entered its third decade of economic stagnation, demographic decline and toxic politics; and once-estranged countries such as India and Vietnam have become promising but demanding partners. America has changed too. It is constrained by a war-weary population and a stifling government debt burden.

The big question is where the United States fits into this changed Asia. Its current approach appears to be a mixture of updated Asia strategies of old and tactical responses to various demands of Asian competitors, allies and partners—some wanting the United States to be a guarantor; others wanting it to be a balancer; and yet others viewing America as an opponent. What is missing is a careful reappraisal of Asia’s new strategic dynamics, a hardheaded assessment of what America’s Asian interests are and a considered approach to fulfilling these interests.

Such a reappraisal requires a proper understanding of the pillars of America’s successful Asia policies in the last quarter of the twentieth century. It should include an analysis of the fundamental changes that have undermined these pillars and will likely erode them further in coming decades. It must then identify American interests within the new Asia and find the best policy levers for securing them...