Making Greenland Strategically Usable: U.S.-Danish Security Cooperation and Alliance-Enabled Militarisation in the Arctic, 1941-1968

How did Greenland become a platform for recurrent U.S. defence activity while remaining under Danish sovereignty? Existing scholarship explains strategic demand, alliance access, institutionalisation, and hierarchy, but not how site-specific permission becomes repeatable capacity. This article develops negotiated territorial conversion, a sovereignty-preserving process allocating complementary rights, enacting them organisationally, and maintaining them through intergovernmental correction. A theory-building process trace of agreements, diplomatic and defence records, technical material, and scholarship follows the U.S.–Danish Greenland regime from 1941 to 1968. The evidence confirms the 1951 legal allocation of construction, movement, supply, communications, and jurisdictional rights; material capacity at Thule; recurrent airborne activity under a standing service rule; and a 1968 correction requiring Danish consent for peacetime nuclear storage and overflight. The allocation-to-routine transmission remains plausible rather than confirmed. Greenland therefore confirms the model’s components and Denmark’s retained capacity to narrow disputed uses, but not the full causal chain across missions.