I've recently post a thread on the subject on this board.
Best way is getting ride of D'Argenlieu and put Leclerc instead.
In OTL Leclerc treated with Ho all the year 1946, even reaching an agrement in spring 1946.
But the conference to apply this agrement, located in Fontainebleau in summer 1946 failed, but this did not ended peace efforts.
Ho-chi-Minh REALLY wanted peace at the time, and another agrement (dubbed a modus vivendi) was found with Marius Moutet, french minister of colnies, in september 1946.
Alas, D'Argenlieu managed to obtain the war he wanted in november when he ordered Suffren cruiser to shell Saigon, kiling hundreds.
D'Argenlieu always disagred with Leclerc and wrecked his talks with Ho-Chi-Minh various times.
Really, get ride of Admiral D'argenlieu,put Leclerc instead, then send the Suffren back to France.
Moutet and Leon Blum formed a governement in december 1946 and they will back Leclerc in his talks with Ho. In OTL both tried to avoid war in January 1947 but it was already too late, contacts with Ho had been broken early december.
Then you can avoid Indochina war.
