In August 2023, the U.N. completed an operation to remove 1.1 million oil barrels onboard the FSO Safer, a decaying oil supertanker off Yemen’s Red Sea coast. The FSO Safer had been abandoned ever since civil war broke out in Yemen, leaving it at risk for a significant oil spill that would have resulted in environmental, economic and humanitarian catastrophes and required tens of billions of dollars in estimated clean-up costs. The United States played a key role in the FSO Safer operation, which has been lauded for its creative, behind-the-scenes diplomacy and serves as a model for preventing future crises and coordinating across the international system.