Japan's attack on Pearl Harbor on 7 December 1941 brought the United States into World War II, and the attack on Hong Kong the next day brought Britain and the Commonwealth to war with Japan. Mitsui wrote the Minister of National Defence on behalf of Japanese-Canadian veterans pledging "their unflinching loyalty to Canada as they did in the Last Great War". Nevertheless, existing anti-Japanese discrimination only increased as Japan became a war enemy, exacerbated by reports of the brutality of the Japanese forces in Hong Kong. Japanese Canadians were labelled enemy aliens and suspected of spying for the Empire of Japan.