Johannesburg — If South Africa anticipates a peaceful settlement in Namibia (South-West Africa), you would never know it from the government's new plan to increase the size of its military.
The South African Defense Force wants to hold onto its trained soldiers for a far longer period of time, and it is asking Parliament for the authority to require service of every white male from age 17 to 60.
Behind the proposal is the government's conviction that its security is increasingly threatened and that without more authority to require service it faces a manpower shortage.
The government perceives a growing internal guerrilla threat and the possibility of a conventional military challenge from neighboring countries, says Prof. Michael Hough, director of the Institute of Strategic Studies at the University of Pretoria.
These perceived threats include greater resistance from Angola in cross-border raids from Namibia and possible involvement of a neighboring African state in the event of a ''general uprising'' in South Africa.
The scope of the military expansion suggests the government ''is planning to hang on to South-West Africa,'' says Paul Moorcraft, a lecturer in international relations at the University of the Witwatersrand.
A Defense Force spokesman discounts this analysis. ''The solution of the South-West Africa problem does not lie with the Defense Force,'' he says. ''It is a political problem. From our point of view we can only plan for any eventuality.''
But the planned military buildup does seem to indicate that at least for the moment the South African government is prepared to pay the economic cost of a defense strategy that includes the border war in Namibia. Some analysts view the cost of the war, about $1 million a day, as one of the factors pushing South Africa toward a settlement on Namibia.
The Defense Force says the mounting threat to South Africa stems from Russian designs on the country. Its spokesman said the government has evidence that Soviets have shortened the time span in which they want to gain control over South Africa through surrogate terrorist organizations.
''They would like to get South Africa over and done with by 1985,'' he said.
Restrictions on publishing defense-related information limit the ability of South Africa to determine the extent to which its interests are threatened from the outside. Those critical of defense expenditures see the outlays as being used to keep white Afrikaners in power rather than to support a legitimate national defense.
The new conscription plan indicates the defense force is having difficulty meeting its needs in a way that does not create economic problems. South Africa is growing short of skilled white manpower.
The government was reportedly considering mandatory service from Coloreds (persons of mixed race), Asians, and women. This idea was eventually dropped.
The bill will not change the two-year service period for white males in the citizen force. But it expands the requirement for men who have already performed their two-year term from the present 240 days over 8 years to 720 days over 12 years. This approach was seen as less harmful to the nation's manpower needs than extending the intial period beyond two years.
The other basic change would give the government authority to require service in its commando force, now voluntary.