For more than a decade, the United States has faced a relentless and heartbreaking increase in fatal drug overdoses driven by synthetic opioids. A new analysis suggests this trend has suddenly reversed due to a major disruption in the global supply chain of illicit fentanyl. Published in Science, the study indicates that regulatory actions taken by the Chinese government, following high-level diplomatic engagement with the Biden administration, may be the primary driver behind this unexpected decline in mortality.