The dollar's status as the world's preeminent currency, together with the U.S. military, has underlain American power since World War II. In a sweeping review of one of the most seminal yet least noticed developments in international affairs, Gal Luft and Anne Korin describe how an emerging coalition of revisionist countries, rogue governments, techno-visionaries and sanctioned entities, buttressed by innovations like blockchain and 5G, are working to push the dollar off of its reserve currency throne.It would not be the first time. Preceding the dollar, five consecutive currencies, each belonging to a superpower of the time, ruled the markets. Each predominated for roughly 80-100 years, and as it tumbled to irrelevance it accelerated the decline of the empire behind it.Are we due for a rerun?The slow moving shift from the dollar may be the single most important factor determining the future of American power. Arresting this trend will require Americans to make tough choices.Luft and Korin are co-directors of the Washington, DC-based Institute for the Analysis of Global Security (IAGS).