Until the 1970s, South Africa's apartheid government had placed a disproportionate emphasis on civilian law enforcement and the maintenance of internal security. However, a Cuban intervention in Angola, and the escalation of the South African Border War convinced the government that it faced a serious external threat. In 1978, the premiership was accepted by PW Botha, a former South African security chief, and defence expenditure spiraled upwards. Armscor, then a relatively new entity, was charged with modernising the arsenal of the South African Defence Force (SADF). This was a difficult task, as a United Nations arms embargo on South Africa, promulgated in 1964, became mandatory in 1977. Some of the SADF's preexisting hardware was trying to maintain, and any national defence establishment would encounter hurdles in keeping these systems operational without access to foreign technical support as well as new deliveries of parts and equipment.