Distant Early Warning Line

The Distant Early Warning Line, also known as the DEW Line or Early Warning Line, was a system of radar stations in the far northern Arctic region of Canada, with additional stations along the North Coast and Aleutian Islands of Alaska, in addition to the Faroe Islands, Greenland, and Iceland. It was set up to detect incoming Soviet bombers during the Cold War, and provide early warning of any sea-and-land invasion.

The DEW Line was operational from 1957 to the late 1980s and it was the northernmost and most capable of three radar lines in Canada and Alaska; the joint Canadian-US Pinetree Line ran from Newfoundland to Vancouver Island, and the Mid-Canada Line ran somewhat north of this. Between 1988 and 1993, most stations were deactivated. Those that remained were upgraded as part of the new North Warning System.

Introduction

The shortest (great circle) route for a Russian air attack on North America is through the Arctic, across the North Pole. The DEW Line was built during the Cold War to give early warning of a Soviet nuclear strike, to allow time for US bombers to get off the ground and land-based ICBMs to be launched, to reduce the chances that a preemptive strike could destroy US strategic nuclear forces. The original DEW line was designed to detect bombers and was unable to detect intercontinental ballistic missiles (ICBMs). To give warning of this threat, in 1958 a more sophisticated radar system was constructed, the Ballistic Missile Early Warning System (BMEWS).