西貢條約
In 1873, Philastre returned to the French colonial service in Indochina. Philastre played in important role in mediating between the French colonial authorities in Annam and the royal court in Huế. In 1874, Philastre negotiated the Second Treaty of Saigon with the Annamese court. He also served in Cambodia. He left Indochina in 1889.