A broad transit route rather than a narrow strait

Unlike Gibraltar or Malacca, the GIUK Gap is not a narrow waterway that can be closed with a single barrier. Its geography still channels movements between northern Europe and the wider Atlantic, favouring defenders who can sustain surveillance across a large area. SOSUS and later integrated undersea surveillance systems helped track submarines approaching the route, but the width of the gap continued to consume ships, aircraft, sensors, and crews. The same passage matters in both directions, funnelling NATO forces north as well as Soviet forces south. RAND's contemporary analysis also treats control of the gap as a political question because Greenland, the Faroe Islands, and Scotland sit within changing constitutional debates. Maintaining access therefore requires patrol forces and a convincing case for NATO's local economic and security value.