People of Japanese heritage, even those born in Canada, were relocated to internment camps in the interior. (photograph by Tak Toyota, courtesy Library and Archives Canada/C-46350).

On 7 December 1941, Japan attacked the American naval base at Pearl Harbor on the island of Oahu, Hawaii, putting the United States, together with allies such as Canada, at war with Japan. Canada's first significant losses of the Second World War were the soldiers who died in a failed mission to defend Hong Kong from the Japanese. In response to growing fears that Japan might bring the war across the Pacific, the federal government stationed 34,000 troops in British Columbia.

The rumors in British Columbia were fantastical—Japanese spies, Japanese admirals disguised as fishermen, Japanese submarines readying to attack. Lingering racism and prejudice against Asians flared, as fears were voiced that the sympathies of those of Japanese racial origins lay not with Canada but with Japan—ignoring that most Japanese Canadians were Canadian-born and had never been to Japan. In the mounting hysteria, some saw danger in Japanese residents living in a coastal province, danger again in some of them owning boats—despite many early Japanese having pioneered British Columbia's coastal commercial fishery.

In 1942, the federal government decided to "evacuate" all residents of Japanese origins. The government confiscated and sold their businesses and homes for depressed prices, sent males to work in road camps or sugar beet farming projects in Alberta and women and children to isolated towns in south eastern British Columbia. Canada interned 22,000 in all. It did not act alone; the United States interned 120,000, and Australia interned 7,000. At war's end in 1945, the Canadian government encouraged the Japanese to re-settle east of the Rockies or to leave for good for Japan. Most settled in Alberta and Ontario. In 1949, the government decided they were free to choose where to live.