Notwithstanding the new attention to apartheid bubbling up around it, the Reagan administration sees no need for any fundamental policy review. It thinks that its policy of the last four years is working, that as it becomes better known it will become more accepted, and that the changing political circumstances may make it work even more effectively.

Tactics are another matter. In this category, as the administration sees it, falls the question of "quiet diplomacy." There change is evident. In the last week, President Reagan has spoken up with new feeling to condemn apartheid and show sympathy for its victims. He seems determined to rebut the suggestion of personal insensitivity and to keep his critics from grabbing the issue away from him.

On the mean right, American blacks are being denied credit for moral anguish and instead are accused of having low political motives in starting up the demonstrations. The Heritage Foundation's new report barely mentions apartheid and urges that Pretoria be "rewarded" for "liberalization" achieved so far. Mainstream conservatives, however, are with the president in starting to accept more openly a moral and political obligation to speak out for individual freedom even in anti- communist South Africa.

So quickly have conservatives departed from their earlier discretion or seeming indifference that it now becomes a real possibility for the president at least to hold his own in the battle for American opinion that an angry black group began at Thanksgiving in front of the South African Embassy. For it seems that what most committed people want, or what they want first, is simply a display ofpresidential feeling that matches their own outrage. The president is being asked, for openers, only for a small shift in his public attitude.

You could say that a shift in tone is a change in substance, if it helps relieve fearful white South Africans of the notion that Reagan can be counted on to pull their chestnuts out of the fire. If they come to believe Reagan demands a steady yielding of apartheid as the condition for a close American tie, that could make a difference.

What the administration considers its substantive policy, however, remains in place: "constructive engagement," aimed at the mutually reinforcing targets of 1) easing conflicts between South Africa and its neighbors and 2) breaking down further the siege-minded Afrikaner elite's resistance to entering an open-ended process of peaceful political change.

President Reagan seems to have been at once dismayed and relieved at Nobel laureate Desmond Tutu's level of understanding of his policy in their recent meeting. He and key aides were dismayed that the United States was not being given credit for its 16 or so public statements against apartheid just since September, or for a strategy that has seen South Africa break the hallowed principle of a white power monopoly by extending limited political rights to Asians and Coloreds, and that has put the issue of black political rights on the South African agenda for the first time. He was relieved to find it would not take such great leaps forward to come within the range of Bishop Tutu's and many others' concern.

This is crucial. "Most important, I think," Tutu said Sunday, "would be if the administration made it quite clear that they would no longer be protective of the South African government" in voting on Security Council resolutions -- certainly a rather mild demand.

In fact, when you look closely, most critics have a rather realistic sense of the possible. Few are pressing seriousl to remove such instruments of American influence (and profits for whites and jobs for blacks) as the American corporate presence. Rather, they desire American influence to be wielded to greater effect -- a desire that the corporations, following the Reagan lead, are already responding to.

So there is room for close argument about how to manipulate the available levers but -- once the matter of presidential good faith is established -- there is not all that much room, I think, for a great debate.

Some in the administration feel victimized by an inattentive press and by "a determined minority" of critics who characterize American policy as a "love-in." Other critics, however, are considered more open. Rep. John Conyers demanded on television on Sunday that the administration "stop supplying South Africa with . . . military support" and halt economic aid. The State Department's Chester Crocker replied that there is no military link at all and that the only economic aid goes to train black.

All of this is to say that the American political system is honing a new approach to apartheid. Let's see how it develops.