sentences:  At this time, there was one major obstacle, the armored units in the capital and its outskirts.The plotters needed help from Colonel Dương Hiếu Nghĩa, one of the leading Đại Việt officers and temporary head of the Capital Armored Command, who was key to the coup's success.A friend and appointee of Minh, Nghia caused difficulties by failing to respond to Thiệu's order that all armor be moved north out of Saigon to Thiệu's 5th Division headquarters at Biên Hòa, a satellite city on the northeastern edge of the capital.