The rise of clean energy has achieved unstoppable momentum. And yet much about the clean energy transition remains uncertain, from how and when global fossil fuel consumption will decline, to how a shift to low-carbon energy sources will affect geopolitics. This research pillar explores the implications of the clean energy transition for international affairs and proposes measures to support the expansion of clean energy, with a special focus on the industrial and foreign policies of the United States, Europe, and select emerging markets. Our Carbon to Clean Tracker is part of this pillar.