War on the Rocks – Sea control has changed. In recent years, there has been a quiet revolution in maritime strategy that has seen navies increasingly expected to exert greater levels of control over more of the world’s oceans, more of the time. Whether it is NATO forces protecting critical maritime infrastructure in the Baltic, Pacific Island nations requiring maritime domain awareness to protect against illegal fishing, or Chinese coast guard and maritime militia vessels occupying features in the South China Sea, navies across the globe are confronting major challenges and are being forced to operate in new and novel ways. Behind all of this is a change in the value that states place upon the seas. Drawing on work from my recent article in Comparative Strategy, I show how — for many countries — growing areas of the world’s seas and oceans now have considerable economic significance, and value in terms of sovereignty and identity. This newfound value has generated the demand for a new form of sea control, which is radically different from that set out in classical maritime strategy.