*1945 was when Ho Chi Minh declared independence and declared war on the occupying Japanese. Japan also occupied the country from 1940 onwards - so it was . The last year of the occupation was especially brutal, as the Japanese militarists knew they were losing, so they forced the Vietnamese to plant mainly cash crops to sell abroad, leaving the population starving - 0.6-2 million died, which approaches Vietnamese casualties from the war with the US. (The future dictator of the US client state of South Vietnam, Ngô Đình Diệm, had naturally collaborated with the Japanese during the occupation.)
And before that it was the French occupation - which in its last decades had really cranked up the exploitation, flooding the country with opium (which had never been big before), among other ways to extract cash.
*1945 was when Ho Chi Minh declared independence and declared war on the occupying Japanese. Japan also occupied the country from 1940 onwards - so it was . The last year of the occupation was especially brutal, as the Japanese militarists knew they were losing, so they forced the Vietnamese to plant mainly cash crops to sell abroad, leaving the population starving - 0.6-2 million died, which approaches Vietnamese casualties from the war with the US. (The future dictator of the US client state of South Vietnam, Ngô Đình Diệm, had naturally collaborated with the Japanese during the occupation.)
And before that it was the French occupation - which in its last decades had really cranked up the exploitation, flooding the country with opium (which had never been big before), among other ways to extract cash.