How Will We Know When China Is #1?

Aassuming the continued rise of China, when will we know—indeed, how will we know—that Beijing has knocked Washington off the top spot? The various gauges of national power favored by international-relations scholars—military spending, total industrial output, population, territorial size and so forth—have the virtues of being concrete measures of material wherewithal and at least open up the possibility of comparing the United States and China along objective dimensions. Yet such measures are also highly discrete from one another—that is, they constitute an array of fragmented indicators that are difficult to synthesize into a single index of national power. Attempts to create such aggregated measures of power abound, but often end up failing basic “sniff tests.” And, of course, actual influence in international politics is even harder to grasp, let alone measure.