BLACK NATIONALIST guerrillas have struck a telling blow at the security, physical and psychological, of white South Africa. From hit-and-run raids on random targets, they have moved up to a well-planned and coordinated attack on three formidably guarded strategic installations, an oil refinery and two oil-from-coal plants. These plants are the cutting edge of South Africa's policy of trying to become self-sufficient in strategic imports. The attacks on them represent the African National Congress' policy of trying to show that self-sufficiency won't work. In South Africa, the war is on.

Why did the ANC escalate now? The obvious answer is that it was ready. It is in the business of armed rebellion and this is its most spectacular success to date. In another sense, the raids are a tribute of sorts to the efforts undertaken by the ruling white minority to forestall armed struggle and revolution by timely reform. The government of P.W. Botha has embarked on a program to reduce the economic, social and legal burdens that whites place on blacks, Asians and coloreds (people of mixed race), and to share some measure of political power with them. Whether the purpose of this program is to move toward full equality or to avoid moving toward full equality is open to debate -- and likely also to be in part determined by events. But it is a serious program and it is forcing new political requirements on all the actors. Obviously, the ANC recognizes a requirement to make its own presence and program known.

The latest raids cannot fail to sharpen the question before white South Africans of whether it is better to stand firm or to accelerate reform. Since the eventual security of whites cannot be guaranteed under either approach, it seems wise for outsiders not to offer advice too glibly. Two things, however, do look clear. Time is short: optimists in South Africa think there are two or three years -- pessimists that there are none. And though some whites and some blacks in South Africa reject the idea, it surely is preferable to route as much change as possible through a political process, rather than into a contest between white law and order/repression and black revolution/terror.

The problem here is that whites are not letting blacks into a real national political process. At most, still, whites are designing incomplete political solutions for blacks. The clearest indication that whites understand -- and some do -- their own overwhelming interest in opening politics to blacks would be the release of black political prisoners who have a claim to national leadership. First among them is Nelson Mandela, former president of the ANC, the group that exploded the bombs.