On his penultimate trip to Asia this week, U.S. President Barack Obama will have an opportunity to survey the changes that have occurred there during his time in office. As he does, he will find the region much different than it was at the start of his presidency. For the Asia-Pacific region, a single phrase has come to define Obama's administration. In late 2011, as the United States finalized its intended withdrawal from Iraq, the president declared a great American pivot to Asia. The idea counteracted Washington's dispirited Middle Eastern policy, evoking a massive transfer of U.S. forces and resources to the Asia-Pacific area. Subsequent domestic and international interpretations envisioned the pivot as a tangible thing to be measured in the tonnage of U.S. warships deployed in the region. This proved to be inaccurate....