Over the next two decades, the relative power of major international actors will shift markedly. Around 2030, after nearly a century as the preeminent global economic power, the United States will be surpassed by China as the world’s largest economy. With its trade in goods expected to nearly double that of the U.S. and Europe, China’s international economic clout will reach new heights. By 2030, India will become the world’s most populous country and third-largest economy, while Brazil’s economy will rank fourth in size. India and Brazil will join China at the high table of 21st century international politics alongside the United States, even as the relative weight of Russia and Japan diminishes. The European economy will remain in the top tier, but it is not clear whether Europe will be able to act with common purpose to leverage this source of strength.