In July 1979, Pol Pot established a new headquarters, Office 131, on the western flank of Mount Thom. He dropped the name "Pol Pot" and began calling himself "Phem". In September 1979, Khieu announced that the Khmer Rouge was establishing a new united front, the Patriotic Democratic Front, bringing together all Cambodians who opposed the Vietnamese occupation. Senior Khmer Rouge members began disavowing the cause of socialism. The group members stopped wearing uniform black outfits; Pol Pot himself started wearing jungle green fatigues and later Thai-made safari suits. Short believed that these changes reflected a genuine ideological shift in the Khmer Rouge. In October, Pol Pot ordered an end to executions, a command which was largely followed. In November 1979, the United Nations General Assembly voted to recognise the Khmer Rouge delegation, rather than that of the Vietnamese-backed government, as the legitimate government of Cambodia. In December, Samphân replaced Pol Pot as prime minister of Democratic Kampuchea, a move that allowed Pol Pot to focus on the war effort and which was perhaps also designed to improve the Khmer Rouge's image.