Zbigniew Brzezinski's russet eyebrows rise and fall, his eyes glint and his wry hands shape the air in front of him as he seeks the word, coming slowly for once. "Bite," the president's national security adviser says to an aide drafting a weapons speech, "it lacks bite in the second part and a feel for knowledge of weapons systems."

It is mid-morning in the West Wing of the White House, some three hours after Brzezinski has delivered the nation's most important daily five- to 10-minute news digest to an audience of one, Jimmy Carter. Using the same staccato, accented verbal skeins of fact and analysis that once mesmerized graduate students and now provide the president a capsule of the day's outlook for Chad. Israel, Korea or other nations, Brzezinski is toughening up an important policy speech.

Messages with "bite" are tumbling out of the national security adviser's office with increasing intensity as part of an important new Washington phenomenon - the Coming Out of "Zbig," as the Polish-born scholar of communism and cybernetics is known to the president and other friends.

There was a year of high impact but low profile operations inside the White House, during which Brzezinski concentrated on global policy designs that have brought little in the way of immediate returns for Carter. But in recent weeks Brzezinski has been darting about town raising alarms through press briefings about the growing Soviet and Cuban presence munity leaders with angry answers in Ethiopia, confronting Jewish comto their criticism of the administration's Middle East policy, and issuing general warnings that the resolve and toughness of this administration should not be underestimated.

That, for example, was the thrust of his message to Senate staffers during a December meeting to rally support for the Panama Canal treaties. As he now recalls the language he used at the time, Brzezinski agreed with a questioner that the fact that "some people think of us as being soft" would cost the administration some votes in the Senate.

"If there was a situation in which in fact we could prove we weren't soft, those people would probably support us more," Brzezinski recalls answering.

The eagerness to show "resolve" comes as no surprise for those who have watched Brzezinski's determined climb - from campus into the Democratic Party's mainstream foreign policy establishment and now to the top of the National Security Council. But the timing of his "No More Mr. Nice Guy" theme appears to carry far more than stylistic importance.

While they are not prepared to say so publicly, Brzezinski and his staff appear to have concluded that the plateau where Soviet-American relations have rested for most of the Carter administration is likely to turn into a sharp downward slope in coming months, with growing dangers of serious confrontation.

Upper echelon State Department officials, some of whom agree with that assessment, are disturbed that Brzezinski's insistence on drawing lines against the Soviet's in distant places like the Horn of Africa will turn that view into a rapidly self-fulfilling prophecy. Moreover, they fear that Brzezinski is trying to use his advocacy of a tougher approach to expand his bureaucratic power, at State's expense.

Precedents for the academician-turned-man-of-action are still vivid in Washington's memory. Since the beginning of the Kennedy administration there were Roger Hilsman, the Bundy brothers (McGeorge and William), the Rostow brothers (Walt and Eugene) and, most recent of all, Professor Henry Kissinger.

Like many of his predecessors, Brzezinski often seems determined to demonstrate that an Ivy League professor can operate in the world of hard realities and can be as tough as the Wall Street lawyers and hard-nosed bureaucrats at the top of the foreign policy hierarchy.

During an interview in a busy Washington restaurant last week Brzezinski touched several times on this theme of toughness. His own recent utterances, he said, "underline something that I happen to know for a face - namely that the president is tough, that he is very, very responsible, very measured an he is not to be pushed around. Neither is the United States."

Moving easily through the crowded restaurant without the heavy security apparatus Kissinger required around him, Brzezinski did not elicit the stares of instant recognition that would have greeted his predecessor. Brzezinski's stiffly brushed and disciplined hair, which is plentiful and shaded the color of winter aples, his slight build and clipped, nasal Polish accent have not erased the memory yet of Kissinger's guttural diction, careful parsed sentences and portly presence in the popular imagination.

That is partly intentional. Carter's foreign policy team came to office determined to be seen as totally different from Kissinger, including dropping Kissinger's assiduous quest for the spotlight and celebrityhood.


Brzezinski's "historical optimism" was declared to contrast markedly with Kissinger's brooding global view, and policies were designed to reflect that. Buoyed by the post-Vietnam temper of the American public, the administration pronounced itself ready to build new policy structures with Europe, Japan and the Third World to replace the balance-of-superpower politics Kissinger played with Moscow.

A year in office has eroded much of that initial optimism, lessened the drive to be different for the sake of not being Kissinger, and brought the U.S.-Soviet relationship back to the policy forefront. Diplomats are carefully examining Brzezinski's recent flurry of activity for signs that the "real" Carter foreign policy is beginning to stand up.

Though he lacks Kissinger's celebrity status, George Ball's deep experience with the Washington foreign policy establishment or McGeorge Bundy's cold technical skills, Brzezinski does possess one asset that all these potential rivals lack - Jimmy Carter's trust.

Responding to the president's insistence on a more open and decentralized policy machine, Brzezinski has overhauled the National Security Council apparatus by shearing away many of the tightly centralized control mechanisms that Kissinger established and used to acquire a grip on policy.

But Brzezinski has still been able to exercise broad influence on administration priorities, primarily through his close relationship with Carter. He was the primary mover, White House and State Department sources report, in making the Panama Canal treaties the flagship of Carter's first legislative program, arguing that a quick victory on Capitol Hill would establish Carter's international credentials and open the way for a string of other triumphs.

Brzezinski now meets three times a week with Hamilton Jordan, the president's top aide, and other domestic policy advisers. He is on the telephone five to 10 times a day with Secretary of State Cyrus Vance.

"When I came to Washington there is no doubt that the big expectation was that there was going to be a nasty and furious fight between Cy and me," Brzezinski said. The expected power struggle never materialized, he said, and he and Vance "are good friends, even though we occasionally disagree on substance, sometimes very sharply. We both know that reality is complex and can be interpreted in many ways."

As described by Brzezinski, those differences stem in part from bureaucratic imperatives.

"My job is to think about the national security of the United States," he said. "That's what I have to think about every day, every morning and every night . . . I think it is very important that there be a clear voice in this administration that points to the national security implications of trends and developments. It is very easy to be drawn to attractive solutions which generate good atmospherics."

His working relationship with the non-combative, low-key secretary of state appears to be untroubled. But there is a clear divergence between the global view of dealing with the Soviets that Brzezinski brought to the White House from Columbia and that of the more traditional area-studies experts who staff the upper levels of the State Department.

At Columbia, Brzezinski was an academic outsider, setting up his own research institute, to concentrate on specific issues of East-West conflict. His writings, lectures and speeches before taking office suggest this dichotomy, expressed in simplistic terms: He favors dealing roughly with the Soviets from time to time as a matter of strategy, to impress them with one's resolve, while the State Department hierarchy favors more carrot and less stick.

Brzezinski has brought in an experienced former Foreign Service officer and NSC staff memerb, David Aaron, as his debut to handle much of the bureaucratic byplay of policymaking. But he does not appear to be acquiring strategic allies within the power structure below Vance or in other departments.

Brzezinski has backed two of his closest friends for top jobs at the Defense Department, but both Samuel P. Huntington and Henry Owen have returned to the NSC staff after failing to win over Defense Secretary Harold Brown, a skillful user of the bureaucratic tactical skills that Brzezinski is still learning.

Owen was Brzezinski's boss during a two-year stint on the State Department's Policy Planning Council in the mid-1960s, when Brzezinski was a staunch advocate of the Johnson administration's Vietnam polices. Vietnam is one of a number of cases where Brzezinski has reversed fields after admitting error in initial, strongly argued analyses.

"On the whole, my views are strategically consistent, tactically very fluid," Brzezinski said. "I'm prefectly willing to change tactical positions because the world changes. Anybody who maintains that one has to be constant in one's views in every respect for decades is a jerk."