Hồ Chà Minh had been leading a Vietnamese independent movement against French imperial rule since 1941 and by September of 1945, using the chaos of the end of the war and a devastating famine that killed more than 2 million of his people, he would garner massive support in the North due to a relief effort he helped organize to help the poor and starving.
This move meant that when the French did arrive to take back the country the vast majority of those living in the north sided with the Viet Minh.
Although outnumbered, the French forces had superior firepower and the support of the French Navy which allowed them to easily take back control of Hanoi and scatter the Viet Minh, causing them to flee into the countryside and jungles.
Unfortunately for the occupying French, instead of capitulating, Hồ Chà Minh and his troops would engage in a campaign of guerrilla warfare, a campaign that would last until 1949 and force the French to the negotiating table.
The French would grant Vietnam its independence but with a huge caveat attached, they could have their independence but only as an associated state in the French Union.