tự đức continued to hope that vietnamese compliance with the treaty would convince france to return the three southern provinces. in the words of gian, vietnam's full cooperation with the 1862 treaty was necessary to maintain the possibility of a territorial retrocession. the french officers in saigon, the capital of cochinchina, frequently accused the nguyễn court of violating the treaty by quietly supporting continued resistance. in 1867, they took this as a pretext to seize the other three provinces in southern vietnam: vĩnh long, hà tiên and an giang.