It is no secret that detente between the United States and the Soviet Union is in trouble. Accusatory rhetoric as escalated on both sides. The president denies that his policy contemplates any linkage between the strategic arms limitation talks (SALT II) and Soviet behavior in Africa.

But he also keeps telling us that, for all practical purposes, they are linked anyway because a hostile public may resist ratification of a new SALT pact unless the Soviets mend their ways elsewhere. That last premise, it must be noted, is sharply contradicted by public-opinion polls showing overwhelming and unflagging popular support for strategic arms controls.

Notwithstanding all the attention has apparently applied, and the size of the foreign-policy apparatus at his command, I am left with nagging doubts about whether President Carter has settled upon the policy he really wants in this area.

The chief concern of the White House is that the Soviets - with a few of their own advisers, but mainly through some 30,000 Cuban troops - are behaving opportunistically in Africa and thereby violating something called the "code of detente." Without excusing Soviet or Cuban activities, I find the vehemence of the reaction hard to understand and completely out of line with what the president himself has often told us are his priorities.

Before we follow the alarmist course too far, we should contemplate the tragedy for the African nations that will follow if they are treated simply as prizes for great powers to fight over.

Africa will likely remain a continent in turmoil for many years to come, in large part because borders left over from the colonial era ignore traditional tibal identities. Those conflicts will produce pain enough without outside help.

I the superpowers jump in with their sophisticated weaponry and massive firepower, Africa's anguish will be multiplied many times over. So let us first consider the people who live on the battlefield before planning any grand African ventures.

But aren't we only reacting to Soviet action? What will happen if we do not stand up to the Russians in Africa?

In my view, the most plausible answer is that the Africans will themselves supply the resistance. If the Soviets attempt to really control the African governments they have supported, they will inevitably run afoul of the nationalism that is the strongest single force on the continent.

Indeed, they have already encountered those sentiments and have not only been hooted out of Egypt in the Middle East, but also Somalia and the Sudan, and have suffered setbacks in Guinea, Nigeria and elsewhere.

So the alarmist policy is flawed, first, because it neglects the Africans themselves and, next, from the fact that their struggle against colonialism was not waged simply to make room for a new brand of colonialism from Moscow.

Beyond that, the policy has another and still more serious defect - a failure to discriminate between our national preferences and our national interests.

Certainly the president knows that mutual restraint on nuclear arms is something we want for ourselves, to serve our own economic and security interests. It is not a reward for the Russians. Arms control is one of the few areas in which mutual American and Soviet interests can and must be served, even if we remain sharply at odds on other fronts.

Instead of repeating that the American and Soviet interests can and must be served, even if we remain sharply at odds on other fronts.

Instead of repeating that the American people or the Congress might link SALT and secondary issues such as our differences in Africa, the president should take the every opportunity to explain why such a linkage would be a terrible mistake.

Given what we have heard from the president about his commitment to arms control and arms reductions, I suspect he will be haunted for the rest of his days if he discovers that his words about Africa have helped to create a climate in which a SALT agreement cannot be approved in the Senate. That is the risk he is running, and it is one where I think his posture contradicts his own strong aspirations.