In mid-October a ranking European prime minister sent his "Kissinger" to Washington to scout the political terrain. A lunch was laid on, and one of those who came, in the full press of the Reagan campaign no less, was the chief of the Reagan campaign, now-counselor to the president, Edwin Meese III. Not everyone at the lunch had previously known of Meese's interest in foreign policy, but he joined the discussion easily. A mischievous soul suggested that some in the Reagan camp did not fully share the positive view of the prime minister being put forward by Meese. He cut in instantly to assert that Reagan and the prime minister would get along fine.

I thought of this episode the other day while trying to figure out where the power lines may run on the foreign policy side of the Reagan administration.

Already, of course, Secretary of State-designate Alexander M. Haig Jr. has the look of a winner. A world figure, he is experienced, knowledgeable, forceful and presentable. His curtness and theatricality on Watergate, at his confirmation hearings, put me off. Is that the way he reacts to pressure? But, I note, most people seem to feel he is coming out of the hearings with enhanced prestige.

Certainly Haig is assembling a first-rate (and, like him, hard-edged) policymaking team. At the Pentagon, by contrast, Secretary-designate Caspar Weinberger and his appointees so far seem readier to manage the defense establishment -- no mean goal -- than to vie over policy.

In his testimony Haig announced that "the president needs a single individual to serve as the general manager of American diplomacy. President-elect Reagan believes that the secretary of state should play this role." He went on: "As secretary of state, I would function as a member of the president's team, but one with clear responsibility for formulating and conducting foreign policy, and for explaining it to the Congress, the public, and the world at large." This made the senators beam, and they beamed more when he said: "The assistant to the president for national security would fill a staff role for the president."

Hmmm. Richard V. Allen, Reagan's national security adviser, has cheerfully agreed to drop into a staff crouch. He canceled out of a press lunch this week, although -- an indication of another sort -- he is landing heavyweights (like Harvard's Richard Pipes) for his staff. But Haig is making a mistake, the same one made by Secretary of State Edmund Muskie, if he thinks that by having the president fence the national security adviser off from legislators, foreigners and journalists, the secretary of state will emerge as the top dog.

That is the lesser part of it. Those public and operational functions of Henry Kissinger (in his White House days) and Zbigniew Brzezinski were only symptoms of their frictions with the secretary of state. The causes, aside from their personal qualities, were: their proximity and availability to the president, their freedom from having to represent a departmental interest and their perception of the president's general political as well as foreign policy requirements. None of that has changed.

Almost every foreign policy problem is more than a foreign policy problem and, as a result, the president -- any president -- is always going to have to balance off foreign and domestic interests and constituencies, mediate arguments among Cabinet officers and assert a presidential and/or national interest. In recent administrations the national security adviser has been better able than the secretary of state to see problems the way the president sees them. This has been the key to his power.

Some people can foresee Haig performing this particular service. He is ambitious, savvy in White House ways and idolatrous of presidential power. Others can imagine Allen, notwithstanding his deference and lesser celebrity, rising into a high profile. He is policy-minded, no slouch at maneuver and knows the Reagan style. Meese is the dark horse.

But consider: a veteran Reagan lieutenant, Meese, with chief of staff James A. Baker III, sits atop the White House staff pyramid. He will run the policy side, and Allen and his domestic policy counterpart will report to Reagan through him. Interagency differences will come to him. Experts recall no similar setup in earlier administrations.

"Don't underestimate Meese," one well-placed observer told me. "He has a razor-sharp mind and an extremely close relationship with Reagan. Meese is not fighting for turf. He doesn't have to. The nature of the problems will bring issues to him."

Added somebody smart: "Meese is formidable. His character will make him the top man in foreign policy. He is wonderfully placid and self-controlled." t