Logo: to the web site of the Swedish Defence University

The ability for a coastal state to freely use the sea is the lifeblood of international trade, both today and historically. Coastal states that wish to use the sea both in peacetime and wartime thus have to be able to assert a degree of control over relevant parts of the sea. This qualitative theory-consuming case study examines the roles in establishing and denying sea control conventional submarines had in the Baltic Sea during the Second World War through Milan Vego’s theories on sea control and sea denial. In earlier research there is a view of conventional submarines as ships mainly suited for sea denial, while other research suggests the roles of conventional submarines in naval warfare could be different in what Vego calls narrow seas compared to open oceans. The roles of submarines in the naval warfare during the Second World War in the Baltic Sea, as a case of a narrow sea, is thus examined in this study. This study uses a design of qualitative theory-consuming case study to examine how and to what purpose submarines were used for sea control and sea denial through analysing historical books and documents on that theatre of warfare. By examining the case of the Baltic Sea during the Second World War, this study has showed that conventional submarines in the Baltic Sea during the Second World War had roles relating to both sea control and sea denial, providing nuance to earlier research and a historical example of what roles in establishing and denying sea control conventional submarines have had in a narrow sea.