Between 1947 and 1957, the United States and Canadian governments established a chain of stations along the Arctic coast known as the Distant Early Warning Line (DEWLINE) to provide warning of a Soviet nuclear attack.
1947年至1957年间，美国和加拿大在北极地区沿岸建立了一系列观测站，称为“远距离预警线”（Distant Early Warning Line, DEWLINE），以侦测苏联核导弹攻击。