Sometimes geopolitical shifts happen by accident rather than design.

Historians may record March 2015 as the moment when China's checkbook diplomacy came of age, giving the world's No. 2 economy a greater role in shaping global economic governance at the expense of the United States and the international financial institutions it has dominated since World War II.

This month European governments chose, in an ill-coordinated scramble for advantage, to join a nascent, Chinese-led Asian Infrastructure Investment Bank in defiance of Washington's misgivings.