Canada's participation in the Manhattan project was critical since the country was one of only two places outside Nazi-controlled Europe -- the other was the Belgian Congo -- with known natural deposits of uranium.

Throughout the 1940s, as Canada helped fuel American bombs, the country carried out its own extensive weapons research, focused on finding the most efficient ways to produce plutonium. By the end of World War II, according to the Canadian Coalition for Nuclear Responsibility, Canada's NRX reactor housed at Chalk River, Ontario, earned a reputation as the most efficient plutonium-processing reactor in the world.

After its revelation in 1945, Canada chose a different path than the other major Manhattan project partner Britain, deciding not to construct its own atomic bomb. The government turned over control of its Chalk River reactors to the National Research Council for civilian energy production.

"We have not manufactured atomic bombs; we have no intention of manufacturing atomic bombs," Canadian Minister of Reconstruction C.D. Howe told the House of Commons on Dec. 5, 1945.

Secretly, however, Canada continued to provide plutonium from Chalk River and uranium to Britain and the United States to fuel their weapons programs, according to author Gordon Edwards in the book, Canada and the Nuclear Arms Race.

At the height of Canadian nuclear production from 1948 to 1959, Canada exported an estimated 12,000 tons of uranium, according to Gordon. And, in his 1966 book Canada's Nuclear Story, Wilfrid Eggleston estimated the Canadians built 517 uranium rods during that time.

Canada has also been associated with U.S. nuclear weapons in other ways. Although the country pledged to refrain from building a nuclear bomb, it did acquire U.S. nuclear warheads for use in its weapons systems, according to John Clearwater a former civilian analyst with Canada's Department of National Defence.

According to Clearwater, from 1963 to 1984 Canada was a nuclear power since its weapons systems at home and at bases in West Germany were equipped with U.S. nuclear warheads. Clearwater estimates, according to the Bulletin of Atomic Scientists, that "at the height of Canadian nuclear deployments, the greatest number of weapons which could have been available to Canada would have been between 250 (low estimate) and 450 (high estimate)."

In 1968, Canada did begin to remove nuclear weapons systems from its bases, leading then Canadian Prime Minister Pierre Trudeau, in his famous speech before the U.N. General Assembly in 1978, to hail Canada as, "not only the first country with the capability to produce nuclear weapons that chose not to do so, we are also the first nuclear-armed country to have chosen to divest itself of nuclear weapons."

But, it was not until 1984 that Canada was completely free of nuclear weapons, according to Clearwater.

Though Canada was one of the first countries to sign the nuclear Non-Proliferation Treaty in July 1968, the country has come under fire for providing India with the reactor India used to produce the plutonium that fueled its first nuclear bomb explosion in 1974.

-- Compiled by Kristina Nwazota for the Online NewsHour