ARE THE RUSSIANS and Cubans coming, or coming harder, in Africa? That much is suggested by the parallel African safaris of Soviet President Podgorny, on his country's first high-level diplomatic penetration of southern Africa, and Cuban President Castro. Certainly South Africa and Rhodesia would like these trips to stir the West's alarm. Their appeal for American support rests on the claim that they are bulwarks against Communist expansion. Many black Africans, and many Americans, also "welcome" trips like Mr. Podgorny's and Mr. Castro's - to spur Washington to try to preempt the Communists by pushing harder itself for black-majority rule.

The American disposition to seek negotiated and biracial solutions in southern Africa unquestionably leaves some part of the field open to countries that are prepared to back military solutions. But that is only one more reason for the United States to look harder for the peaceable way. Perhaps at this point there isn't one. That may mean that on the East-West seesaw the East may go temporarily up in its standing in some African countries. We don't feel, nonetheless, that Africa offers the Kremlin such large or permanent strategic advantage that Washington should try to counter the Kremlin, regardless of racial considerations: no more Angolas, if you will. We would hope, too, that Africans would, in time, appreciate the economic and political advantages of ties with the West. Meanwhile, they should press the Russians harder for development aid - Moscow has been stingy beyond belief.

Mr. Podgorny and Mr. Castro visited the Horn as well as southern Africa. There the situation is very different. In the Horn, there is no consuming element of racial struggle. There is "simply" a tangle of backward societies in 20th century transition. Ethiopia seems to be slipping away from its traditional patron, the United States, and looking to Moscow. Its chief external rival, Somalia, is the object of a political tug of war between its longtime patron, the Soviet Union, and a more Western-oriented grouping headed by Saudi Arabia. The Horn is not so much a region where Washington should seek strategic advantage as one where it should do what it can, which may not be enough, to keep the temperature down. Mr. Carter's interest in reducing Soviet-American naval competition in and around the Indian Ocean is of a piece with this interest.

One can wish the Russians were not mucking about in Africa, promoting violence where political avenues have yet to be exhausted. But much - though far from all - of the continent is vulnerable to certain kinds of Communist intervention. And the Russians, frustrated in the Middle East, seek a stage on which to flex their growing power. There remain at least two sets of restraints. First, the spectacle of Communist adventurism in Africa quite properly feeds into the American perception of Moscow and damages the hopes the Russians may have for better relations. Secondly, in the past, African nationalism has worked to expel foreign presences, including the Soviet presence, and it can reasonably be expected to do so again. In short, if the United States pays fair attention to Africa's legitimate racial and economic grievances, then there is no reason to panic at a Communist safari, even a double one.