The GIUK Gap is a geopolitical concept and a naval choke point in the North Atlantic Ocean, not an Indian act or institution. The name is an initialism for Greenland, Iceland, and the United Kingdom, referring to the two stretches of open ocean between these landmasses. This strategic corridor separates the Norwegian Sea and the North Sea from the open Atlantic Ocean.
The concept's strategic importance dates back to the early 20th century. During World War II, German ships used the gap to break out from their bases to attack Allied shipping convoys. The GIUK Gap became a main focus of naval planning in the 1950s during the Cold War because it was the only available outlet into the Atlantic for Soviet submarines operating from the Kola Peninsula. The mechanism for controlling the gap involved NATO forces, primarily the United States and the United Kingdom, basing their strategy on blocking it. This included installing a chain of underwater listening posts, known as a SOSUS (sound surveillance system), across the gap in the 1950s to detect Soviet submarines.
The strategic significance of the GIUK Gap diminished as the range of Soviet submarine-launched ballistic missiles (SLBMs) increased, allowing submarines to retreat into protected bastions in the Barents Sea. However, the gap has seen a resurgence in importance since the end of the Cold War, particularly amid Russia's increased naval activity and the war in Ukraine. The gap is now a critical node for protecting Sea Lines of Communication (SLOCs) and vast amounts of critical seabed infrastructure, such as data cables, from hybrid threats. The renewed focus connects the GIUK Gap directly to NATO's northern flank defense and the broader issue of Arctic security.