For most of the last century, the preeminent role of the U.S. dollar in the global economy has been supported by the size and strength of the U.S. economy, its stability and openness to trade and capital flows, and strong property rights and the rule of law. As a result, the depth and liquidity...

Since 2001, foreign investors have acquired roughly $5 trillion in U.S. securities - more than doubling their holdings of U.S. equities and bonds - as both official and private inflows have financed record U.S. current account deficits. Although the rapid growth of foreign holdings of U.S....