Canada and the United States Establish the DEW Line

To counter the threat of a Soviet air attack across the North Pole on populations and military establishments on the North American continent, the United States and Canada agreed to establish the Distant Early Warning (DEW) system, consisting of a series of radar stations designed to detect approaching aircraft.

Summary of Event

Even before World War II ended, the Western nations fighting against Adolf Hitler’s Nazi Germany knew that they would soon be facing another enemy—their ally against the Nazis, the Soviet Union. The United States felt especially threatened by the Soviets’ aggressive behavior in Europe and Asia, but Canada was also concerned, because if the Soviets were to launch an air assault on the United States, their route would cross Canadian soil. As a result, shortly after the war ended, both countries began constructing radar Radar sites to provide warnings of Soviet air attacks. Unfortunately, these sites were often close to major population centers and hence afforded barely an hour’s warning—far too little time to conduct wholesale evacuations. A number of military and political strategists in both countries believed that a system integrating the efforts of the two North American countries could prove beneficial to both nations. Distant Early Warning Line
Cold War;Canada
Canadian-U.S. relations[Canadian U.S. relations]
U.S.-Canadian relations[U.S. Canadian relations]
[kw]Canada and the United States Establish the DEW Line (Feb. 15, 1954)
[kw]United States Establish the DEW Line, Canada and the (Feb. 15, 1954)
[kw]DEW Line, Canada and the United States Establish the (Feb. 15, 1954)
Distant Early Warning Line
Cold War;Canada
Canadian-U.S. relations[Canadian U.S. relations]
U.S.-Canadian relations[U.S. Canadian relations]
[g]North America;Feb. 15, 1954: Canada and the United States Establish the DEW Line[04340]
[g]Canada;Feb. 15, 1954: Canada and the United States Establish the DEW Line[04340]
[g]United States;Feb. 15, 1954: Canada and the United States Establish the DEW Line[04340]
[c]Cold War;Feb. 15, 1954: Canada and the United States Establish the DEW Line[04340]
[c]Diplomacy and international relations;Feb. 15, 1954: Canada and the United States Establish the DEW Line[04340]
[c]Military history;Feb. 15, 1954: Canada and the United States Establish the DEW Line[04340]
[c]Engineering;Feb. 15, 1954: Canada and the United States Establish the DEW Line[04340]
Truman, Harry S.
[p]Truman, Harry S.;Cold War
Eisenhower, Dwight D.
[p]Eisenhower, Dwight D.;Cold War
St. Laurent, Louis
Bull, Harold R.
Claxton, Brooke

Before any system could be developed, however, technical problems regarding the capability and reliability of advanced radar systems had to be solved. In the late 1940’s and early 1950’s, a number of scientists were commissioned by both governments to explore the technical feasibility of such systems. In 1952 the Lincoln Summer Study Group, Lincoln Summer Study Group (1952) a conference of scientists meeting in Boston, reviewed the issue once more and assured themselves that technology developed by scientists at McGill University in Canada could be used as the basis for a radar system that would be capable of long-range detection. If placed far enough north, this system could provide as much as six hours’ notice of an impending Soviet attack. The Lincoln Summer Study Group recommended strongly that the U.S. government invest in such a project.

Surprisingly, not everyone in the United States was in favor of creating a strong system of defense. After the war, strategies that were being developed by the newly created U.S. Air Force Air Force, U.S. to counter the Soviet air threat stressed offensive operations. For years, the Air Force fought plans to strengthen air defense systems, fearing that funds for these programs would be taken from money allocated to increase the number of aircraft in the U.S. fleet. Nevertheless, other members of the government, concerned that American cities might be vulnerable to Soviet attack, pressed President Harry S. Truman to commit to some form of national air defense system. Although he deliberated with both military and political advisers for quite some time, shortly before leaving office Truman signed a National Security Council (NSC) order authorizing the development of a comprehensive early warning system to give between three and six hours’ notice of an impending attack. This formal commitment by the United States prompted officials in Canada to step up their efforts to develop and deploy their own early warning systems.

There was some willingness on the part of the Canadians to enter into agreements for joint operations, but the government of Prime Minister Louis St. Laurent was skeptical of American offers. The Canadians were concerned that large numbers of American service personnel stationed in Canada would give the appearance that their nation was somehow little more than a satellite of its neighbor to the south. Canadian minister of defense Brooke Claxton, who had been working independently to build his country’s armed forces, saw the U.S. government’s move toward a joint air defense force as a thinly disguised takeover of Canadian military operations and a rebuke of Canadian sovereignty. Nevertheless, while politicians fumed and feuded, Canadian air force officers began working with counterparts in the United States to build systems for sharing information, thus laying the groundwork for more formal efforts at joint operations that followed in the administration of U.S. president Dwight D. Eisenhower.

When the Soviet Union successfully detonated a hydrogen bomb in 1953, military officials in the United States gave up opposition to deployment of a defensive system. There was now general agreement that early warning was necessary so that the Strategic Air Command Strategic Air Command could launch its bombers before they were destroyed on the ground, which would make it impossible for the United States to launch a counterattack. Another special commission, established in 1953 and headed by one of Eisenhower’s military associates, Lieutenant General Harold R. Bull, again recommended that the United States invest in an early warning network. In February, 1954, Eisenhower approved an NSC recommendation to deploy the system and signed a bill authorizing construction of the Distant Early Warning (DEW) Line. Under the terms of the bill, the United States agreed to pay the full costs of constructing radar sites above the Arctic Circle. As a second line of defense, Canadians built the Mid-Canada Line, Mid-Canada Line[MidCanada Line] a series of stations about midway between the Arctic Circle and the U.S.-Canadian border. Even before these were fully operational, a third line of stations running on both sides of the border, the Pinetree Line, Pinetree Line was installed near major population centers.

Construction of the stations north of the Arctic Circle was a major engineering feat. All work had to be done during the short summers in the region, and materials had to be transported by air or sled to most locations. More than twenty-five thousand people were employed in construction. Sixty-three stations were erected between Alaska in the west and Baffin Island in the east. The stations varied in size. Some were small and intended to be unstaffed. A number were designed to be operated by a crew of three. The major stations were small cities that included housing, dining, and recreation accommodations for larger crews. A complex system of electronic transmissions linked all the stations and various military headquarters in Canada and the United States. Work began on stations above the Arctic Circle in 1955. Despite brutal weather conditions, the entire line of stations was built in two years. The system was declared fully operational July 31, 1957, and integrated into the air defense networks of both countries.


The highly publicized efforts to create an early warning system against Soviet attack raised public awareness in both the United States and Canada about the menace posed by the communist juggernaut. Americans already accustomed to carrying out a number of defensive measures against impending nuclear attack took some comfort in knowing that the two countries were working together to thwart Soviet aggression. Unfortunately, because the radars were designed primarily to detect aircraft, the DEW Line’s effectiveness was severely limited after the Soviets developed intercontinental ballistic missiles (ICBMs) that were similar to those deployed by the United States. Nevertheless, the system of joint command and control developed to coordinate this air defense system evolved into one of the most notable military organizations of the Cold War era, the North American Air Defense Command North American Air Defense Command (NORAD), which was announced on August 1, 1957. Located deep inside a mountainside command post in Colorado, NORAD served for more than three decades as the principal command and control center for air defense operations on the North American continent. Distant Early Warning Line
Cold War;Canada
Canadian-U.S. relations[Canadian U.S. relations]
U.S.-Canadian relations[U.S. Canadian relations]

Further Reading

  • Eglin, James M. Air Defense in the Nuclear Age: The Post-War Development of American and Soviet Strategic Defense Systems. New York: Garland, 1988. Describes the evolution of air defense strategies in the United States and the Soviet Union; two chapters focus on the emergence in both countries of systems aimed at detecting enemy incursions.
  • Jockel, Joseph T. No Boundaries Upstairs: Canada, the United States, and the Origins of North American Air Defence, 1945-1958. Vancouver: University of British Columbia Press, 1987. Analysis of U.S.-Canadian relationships during the years when the two countries collaborated to develop air defenses against Soviet attacks.
  • Lackenbauer, P. W., et al. The Distant Early Warning (DEW) Line: A Bibliography and Documentary Resource List. Calgary, Alta.: Arctic Institute of North America, 2005. Contains a brief history of the creation and operation of the DEW Line; reproduces several key documents regarding the establishment and maintenance of the system.
  • Ranson, Rick. Working North: DEW Line to Drill Ship. Edmonton, Alta.: NeWest Press, 2003. Anecdotes about construction of the DEW Line radar stations provide a vivid sense of the environmental conditions under which the stations were built and operated.

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