The General Assembly wound up a three-month session last week that was marked by a surprising resurgence of U.S. diplomatic power on issues ranging from southern Africa and Central America to the U.N. budget and the composition of the Security Council.

The scope of this success was recognized here by U.S. allies and adversaries alike and generally was attributed to the unorthodox tactics of confrontation and pressure instituted by U.S. Ambassador Jeane J. Kirkpatrick.

"For the first time," said an Arab diplomat with long U.N experience, "it became U.S. policy that if you want to be a friend of America outside the U.N., you have to be a friend inside the U.N."

He noted that Donald McHenry, Kirkpatrick's predecessor under the Carter administration and a paradigm of traditional U.S. diplomacy at the United Nations, "was liked, but people realized there were no consequences if the U.S. was demeaned or ignored. Mrs. Kirkpatrick is not liked. But her power here and in Washington is respected. And now, there are consequences."

One of the consequences befell UNESCO, one of the U.N. specialized agencies. After the United States announced its plan to withdraw a year ago -- a move actively advocated by Kirkpatrick, according to U.S. officials -- other agencies took the hint. The United Nations announced a hiring freeze and the General Assembly voted a partial rollback of a staff pay increase after Kirkpatrick endorsed a successful congressional move to withhold from U.N. coffers the U.S. share of that cost.

Another visible victim was the U.S. aid program for Zimbabwe, which was sharply cut back after that country failed to vote for the Security Council resolution condemning the Soviet downing of a South Korean jetliner in September 1983.

The link between bilateral aid and U.N. voting patterns was strengthened by the institution of an annual "Blue Book," in which the stands of each nation in the assembly -- with or against the United States -- are tabulated for Congress. This was another instance in which Kirkpatrick admittedly has used Congress as a tool to battle the State Department.

"The Blue Book got a lot of attention here," said one of the officials brought to the U.S. mission by Kirkpatrick, "and that was a major factor in our ability to delete condemnatory references to the United States and, in passing, to Israel from a number of resolutions on southern Africa."

The success of this string of amendments -- they attracted broad support even when they lost -- was viewed as the most substantial U.S. achievement of the session. It came on an issue on which Washington's policy is sharply at variance with that of even its close allies, U.S. support for South Africa, and it rolled back an accretion of overt anti-Americanism that dated to before the U.S.-Third World honeymoon era under Andrew Young.

Another factor contributing to U.S. success here, for which Kirkpatrick gives full credit to the State Department, was a long shopping list of U.S. policy positions at the assembly that was distributed to foreign offices around the world last summer in a series of unusually strong messages ("We trust you will instruct" your delegation to vote with the United States). The early date of the demarches enabled the United States to win commitments before delegations arrived in New York.

Kirkpatrick also takes pride in the length of her tenure at the United Nations, the longest since Henry Cabot Lodge in the 1950s, which has enabled her to "know where the levers are and how to make the system work," a veteran U.S. diplomat said.

Kirkpatrick reportedly believes she also has been able to use her trips abroad and her status in Washington to build high-level global contacts, "working like a big-city political boss" by trading off favors -- an appointment with Rep. Michael D. Barnes (D-Md.) for a visiting foreign minister, in return for good will to draw on at the United Nations.

This year, in fact, is the first assembly session at which these policies have borne fruit, enabling Washington to block a Nicaraguan resolution on Central America; to stave off, in cooperation with the Soviet Union, a challenge to the Antarctic Treaty; to influence a significant shift to more moderate representation on the Security Council, and to block challenges to assembly representation for Israel and Grenada.

"The American situation at the United Nations is very substantially improved -- no question about that," Kirkpatrick said at a recent press briefing.

Some veteran U.N. officials point out that Third World nations are responsive to U.S. pressures in part because they have no choice -- the current crises of death and of famine force many to bow unwillingly. "Her policy in a different world context would be a disaster," said one ranking U.N. official. "Look at Daniel Patrick Moynihan. When he was ambassador during the Nixon era similar confrontational policies didn't achieve any success because circumstances were different."

Several Third World moderates said they resent U.S. arrogance and hectoring but concede that their acceptance of U.S. demands has created a recognition by the Americans of the need to deal more actively with the United Nations and pay more heed to Third World priorities.

Another old hand at the United Nations who represents a close ally suggests that the real question is "whether you Americans could have done the same thing -- or perhaps a few things more -- with more carrot and less stick."

He and others also question whether the United States is using in the most effective ways the power that it has developed. "It's not hard to take a cleaver and whack at the U.N. budget," said one former U.S. diplomat at the United Nations. "But it's harder to go down line by line and see what you want and don't want -- there has been no sense of substantive differentiation. Politically what we have done is replace pro-Soviet accretions at the U.N. with anti-Soviet accretions. If commie-bashing was the purpose, it has been as successful as it could be. But there has yet been no attempt to use the U.N. to achieve positive American policy goals."

Kirkpatrick's colleagues at the U.S. Mission concede that most U.S. initiatives thus far have been what diplomats call "disaster prevention." But they say these have laid the ground for positive actions, such as channeling aid to Africa through U.N. agencies and persuading the State Department to use the secretary seneral's mediating talents on Lebanon and Cyprus.

"Those people don't realize that Kirkpatrick is the best friend they've got in Washington," one of her aides said. She fought the State Department to win funding for U.N. programs providing development assistance and helping African refugees, he noted. Other aides maintained that by demonstrating that the United Nations must be taken seriously and can be made to work for U.S. goals, Kirkpatrick has blunted the anti-U.N. tendencies of her own natural constituency on the political right wing.

They also said that Kirkpatrick feels strongly about the need for continuity of her policies here after she leaves the U.N. job, which now is not expected to be before March or April.

Kirkpatrick's effectiveness has also been recognized, in a way, by her Soviet counterpart, Oleg Troyanovsky, who complimented her at a recent diplomatic reception on the U.S. success at the assembly. However, other Soviet officials maintain privately that the hard-line U.S. approach has made diplomacy easier for them here.

Kirkpatrick replied to Troyanovsky, according a source who was present, that the United States was just trying to achieve a status at the United Nations equal to that of the Soviet Union and was making use of some Soviet tactics.

That approach, however, has rankled some Americans here, who concede that the reassertion of U.S. authority at the United Nations was long overdue but who complain that, as one said, "I don't like my country behaving like the Russians. I don't like bullies who push little people around. I don't like success based on raw power. There are things we should stand for; there's got to be a middle ground."