According to his memoirs, Harbi lived underground in France and gathered support for the Algerian independence.
After the Algerian War of Independence, he became an advisor to the new president, Ahmed Ben Bella, and later a member of his cabinet.
According to his memoirs, Harbi tried to resist the increasingly authoritarian approach of the new government and urged Ben Bella to arm the people to avert a military coup.
He believed, like many Marxists in his generation, that popular militias were needed to revolutionise society as well as resist the impending coup.
However, his own insistence on Marxist dogma helped fuel popular as well as political opposition toward him, which culminated in the very coup he had feared.