Washington — Secretary of State Cyrus Vance's resignation leaves American foreign policy in a state of uncertainty that is being viewed with some apprehension both at home and abroad.
In his public statements, Mr. Vance has confined the reason for his resignation to his opposition to the PResident's decision on the abortive Iran rescue operation. But the secretary of state is said to have been unhappy as well with what he regarded as a drift on the part of the United States toward more militant reactions to world events.
Other diplomats associated with Mr. Vance have seen that drift as a matter of more and more politics and less and less professionalism in the making of the administration's foreign policy decisions.
The future course of that foreign policy will depend to a degree on who is appointed to replace Mr. Vance. For the moment, that has not been decided. Deputy Secretary of State Warren Christopher will take over, for the immediate future, as actingsecretary of state. It also is possible that in the interest of continuity, Mr. Christopher will be given the job as secretary.
But it is clear to most observers that whether Mr. Christopher, a close associate and friend of Mr. Vance, gets the job or not, Secretary Vance's departure marks a strengthening of the hand of Zbigniew Brzezinski, President Carter's national security adviser.
This, in turn, has led to a certain degree of negative reaction both on the domestic political front and overseas.
* At home. Quite a few politicians see the Vance resignation as one more sign of ineptitude in the Carter administration's management of foreign policy.
Mr. Vance was well liked and trusted in Congress and he was widely viewed as a steadying influence on the administration's foreign policy. Mr. Brzezinski has few friends on Capitol hill and is widely viewed as impulsive and unpredictable.
* In Western Europe. state Department officials expect the Vance resignation to intensify a persistent lack of confidence in, and respect for, Carter administration foreign policy. As one former associate of Secretary Vance put it, many of the Europeans viewed Mr. Vance as "the only professional in the administration" and Mr. Brzezinski as "a sort of wild man."
* In the Soviet Union. Specialists on Soviet affairs predict the reaction will be mostly a matter of confirming in the minds of the leadership in the Kremlin that cold warriors, or as the Soviets put it, American "circles opposed to detende" have won out. The Soviets for some time have felt that Secretary Vance was a man they could deal with. They have been highly mistrustful of National Security Adviser Brzezinski.
It is considered significant that, for some weeks now, Secretary Vance has been pushing for White House approval to meet with Soviet Foreign Minister Andrei Gromyko in Vienna in mid-May to discuss US-Soviet relations. Mr. Vance's view has been that it is imperative that the US keep lines of communication open to the Soviets both in good times and bad. But apparently because of domestic political considerations, the White House has balked at holding a Vance-Gromyko meeting on the grounds that it might give an appearance of weakness or appeasement on the part of the United States. Both Mr. Vance and Mr. Gromyko were to be in Vienna next month for a celebration of the 25th anniversary of Austrian independence.
It would be a mistake, however, to assume that President Carter's foreign policy will now take the form of a single-minded, hard-line approach. For one thing, the differences between Secretary Vance and national Security Adviser Brzezinski have not always been so clearcut as some commentators made them out to be.
It should be recalled that it was Mr. Brzezinski who exerted the dominant influence on President Carter's speech on foreign policy at the University of Notre Dame in 1977 in which there was scarcely a trace of cold-war attitudes. The stress in that speech that the President proclaimed that the US now was free of an "inordinate fear of communism."
But beyond that, the seeds of ambivalence in PResident Carter's foreign policy can be traced not only to his advisers but also to the thinking of the President himself.
As far back as two years ago, the President had engaged in a considerable amount of cold war-style rhetoric against the Soviet Union only to return, within a matter of weeks, to a more positive view of how to deal with the Soviets.
At times, the President has appeared to reflect his Southern, small-town background and an attitude of "We're not going to let the Soviet Union push us around." At other times, he has been more the evangelist and the idealist -- as when he set forth a vision in his inaugural address of the total abolition of nuclear weapons.
The inaugural address brought from foreign policy "hawks" cries of anguish and charges of naivete.
Secretary Vance was a strong believer in nuclear arms control, and it was he, togetehr with the President, who initiated a policy of attempting to limit the sale of conventional arms overseas. But the strategic arms, or Salt, agreement with the Soviets has been shelved in recent months, and much of the arms sales policy is in limbo.
Mr. Vance's experience as a Defense Department official during the Vietnam war had led him to believe in a negotiated settlement of that conflict. he apparently feared that a more militant policy toward Iran might led to a step-by-step escalation along Vietnam lines --but up to a point where the Soviet Union would become directly involved.