Promoted to colonel, he was sent to Indochina by the Vichy government in November 1940.
He fought in the brief war with Thailand between October 1940 and May 1941.
By 1942 he had been promoted to brigadier-general and was in charge of all French troops in southern Vietnam, although the country was now under Japanese occupation.By 1944, Major-General Sabattier was commanding the Tonkin Division.
He asked Lieutenant-General Eugène Mordant for permission to prepare to fight a guerrilla war in the event the Japanese chose to end French administration.
This would have included establishing supply caches in the mountains.
The request was refused.
Anticipating a Japanese coup, Sabattier put his troops on armed exercise status on 8 March 1945.
Although he and the Provisional Government of the French Republic in Paris hoped to receive assistance from the American Fourteenth Air Force stationed in China, none was forthcoming.
On 10 April 1945, the Paris government appointed Sabattier their delegate-general in Indochina with plenary civil and military authority.
Ensconced in Dien Bien Phu, he concentrated on civil matters and left the military to Major-General Marcel Alessandri of the 2nd Tonkin Brigade.When the Japanese launched a campaign to destroy the French in the mountains, Sabattier led his soldiers on a retreat of 600 miles (970 km) to China in May.
In all some 2,000 to 5,000 soldiers made it to China.
There Sabattier was the highest-ranking military representative of the French government for three months.
He was replaced as delegate-general on 15 August when Georges Thierry d'Argenlieu was appointed high commissioner.Sabattier returned to Paris at the end of 1945.
He wrote a memoire, Le destin de l'Indocine: souvenirs et documents, 1941–1951, that was published in Paris in 1952.