Right about in the middle of Jimmy Carter's presidency, the infighting between the White House and the State Department was fierce; the public expression of U.S. foreign policy was almost incoherent.

Along came Sen. Edward Zorinski (D- Neb.) with a bill designed to tidy things up by making the president's national security adviser subject to confirmation by the Senate and thus available for testimony before Congress.

His target was the incumbent, Zbigniew Brzezinski, whose new volume of memoirs goes a long way to explain why Zorinski was so exercised. The senator thought--for more good reasons than he could have known about at the time--that Brzezinski was throwing his weight around in a way that diminished the role of Secretary of State Cyrus Vance.

The Establishment, represented by past secretaries of state and former national security advisers, was almost uniformly opposed to Zorinski's idea. The Carter administration testified against it, mostly on the grounds that it would rob the president of confidential counseling.

But Brzezinski was uncharacteristically silent. "You may have noticed that I wasn't saying anything," he recalled in an interview the other day, grinning broadly. And now we know why.

His memoirs have attracted the most public comment and controversy for their insider's glimpse of the peccadillos of particular personalities. But he does offer some prescriptions for the future. And not the least interesting of them is his recommendation that "consideration should again be given to making the nomination of the assistant for national security affairs subject to senatorial confirmation."

Brzezinski, in other words, has come out of the closet in support of a congressional constraint that was calculated to clip his wings; he thinks "it would have made me more powerful."

Brzezinski sees two clear alternatives: "secretarial" primacy to which all presidents pay lip service at one time or another by proclaiming the secretary of state to be the principal formulator and executer of foreign policy; and "presidential" concentration of the decision-making process in the White House. He gives a nod to the former as something that worked in simpler times for President Truman and Dean Acheson, Dwight D. Eisenhower and John Foster Dulles.

But his plain preference is for the latter. You don't have to buy Brzezinski's preferences to accept his judgment that the Reagan administration's mishmash fits neither of the two recognizable historical precedents. It is "presidential" one day, "secretarial" the next.

We have seen this administration dismiss an experienced but weak national security adviser and a strong but overly assertive secretary of state in favor of a competent but underassertive secretary of state and a strong but inexperienced national security adviser. The result, as Brzezinski sees it, has been that U.S. foreign policy has become "more and more reactive" as Ronald Reagan's "domestic advisers were seen as checkmating the secretary of state, while the other two major participants in the process, the secretary of defense and the national security adviser, had no major expertise in the area of national security."

The Brzezinski model makes sense. He would have the secretary of state play the role of "chief diplomat" rather than attempting to "coordinate" policy with a co- equal secretary of defense. That would be done by enhancing the power of a national security adviser confirmed by and responsive to Congress--under the strong leadership of an actively engaged president.

But it only makes sense if you find a president with enough energy and the right work habits who will, in turn, fit the right people into the model Brzezinski describes. The Reagan administration is testimonial to the futility of statutory tinkering with the national security policy-making machinery in pursuit of an all-purpose model for every president.