THE WORLD; Why Does the United States Refuse to Pay Its U.N. Bill?

THE Senate made a significant but paradoxical gesture last month when it unanimously passed a nonbinding resolution acknowledging that the United Nations has been making some important contributions to world peace.

Since 1985, the Senate has refused to appropriate the full amount of the standard United States contribution to the world body, on the ground that the organization is inefficient, wasteful and often contrary to American interests. But now it was praising the United Nations for its recent efforts in mobilizing world opinion against the Soviet occupation of Afghanistan, for example, and for helping with a solution to the Iran-Iraq war.

The resolution, sponsored by Senator Claiborne Pell, Democrat of Rhode Island and chairman of the Foreign Relations Committee, concluded that the United Nations benefits American concerns, and that the United States should pay all of the dues it owes.

As the Senate passed Senator Pell's resolution, the United Nations was practically begging the United States to turn over $44 million that Congress has appropriated for 1988 but is withholding pending efforts in the world organization to cut back expenditures and carry out other changes. Secretary-General Javier Perez de Cuellar has warned that if back contributions are not paid up, the United Nations will run out of operating funds this fall. The United States is in arrears by $466.9 million, fully two-thirds of the total of unpaid assessments owed by all the 159 member countries. 'A Dangerous Place'

The standoff reflects a longstanding ambivalence on the part of both the American public and the Government toward the United Nations, which is alternatively viewed as ''a dangerous place'' - in the words of Senator Daniel Patrick Moynihan, a former chief American delegate -and as an institution that seems to be at least potentially valuable as a forum for world peace.

American suspicion of internationalism, and certainly of subjecting the country's freedom of action to group approval, did not begin with the United Nations. It had its most dramatic moment with the Senate's defeat of American membership in President Woodrow Wilson's cherished League of Nations in 1919.

The League was opposed by rightwing nativists and leftist populists alike, who feared that membership in such an international forum could drag the United States into more foreign wars and subject it to manipulation. When Henry Cabot Lodge, the Senator from Massachusetts, called the League ''an evil thing with a holy name,'' he was anticipating by half a century the persistent antagonism expressed in its more extreme forms by bumper stickers reading, ''Get the U.S. out of the U.N. and the U.N. out of the U.S.''

Despite this undercurrent, there is a common perception that at first Americans enthusiastically supported the United Nations. But some analysts dispute this notion.

''There is undoubtedly far less enthusiasm and far greater skepticism today'' than in the late 1940's and 1950's, said Edward C. Luck, the president of the United Nations Association, a private group that has supported American participation in the organization.

But, Mr. Luck adds: ''It is hard to think of a period when U.S.-U.N. relations were truly tranquil or to identify precisely when were the 'good old days' in the relationship.'' Congressional efforts to scale down the American contribution go back to 1949, when it was decided to reduce the United States assessment from 40 percent of the United Nations budget to 25 percent.

Mr. Luck argues that the Cold War cast a shadow over the public's belief that the United Nations could be an effective instrument of international cooperation. The McCarthy period encouraged suspicions of Communist infiltration.

Things definitely turned sour in the 1970's when a coalition of mostly African and Arab countries - generally supported by the Soviet bloc -gained a majority and, from the standpoint of many Americans, turned the United Nations into a body that issued little more than angry and self-righteous rhetoric. Attack on Zionism

The nadir was reached in 1975 when the resolution equating Zionism with racism pushed many Americans toward full-scale disillusionment. The organization's human rights committee never cited the Soviet Union or Vietnam or, until recently, Iran for violations.

Countries that practiced terrorism accused Israel and the United States of being terrorist states. Anti-Semitic declarations were made from the platform of the General Assembly. When Senator Moynihan, who was the American chief delegate at the time of the Zionism resolution, coined the phrase ''a dangerous place,'' the danger he meant was to democratic and liberal values and beliefs.

While many in this country were clearly alienated by the danger cited by Mr. Moynihan, some polls indicated a pragmatic American skepticism about the effectiveness of the world body in promoting peace. Not only, it seemed, had the United Nations become an arena for offensive rhetoric; it made no contribution to improving American-Soviet relations or ending the arms race.

The Reagan Administration has been extremely unfriendly toward the United Nations. Yet here, too, inconsistencies have appeared. Vernon A. Walters, the present American permanent delegate, in his last report on United Nations' voting patterns, claimed that much of the anti-American venom has recently disappeared, while votes important to the United States have had more favorable results. Mr. Walters, like the Senate two weeks ago, has acknowledged that in such areas as Afghanistan and the Persian Gulf the organization is playing a useful role.

In testimony before Congress, Mr. Walters said he favored restoring full American contributions to the organization. But the Reagan Administration has, until now, refused to certify that the United Nations is making satisfactory progress toward change, a condition that must be met before the $44 million can be released.

After the Pell resolution was passed, there was a move in the Senate to remove the certification requirement. But it was defeated last week in an appropriations subcommittee, most of whose members had voted just the week before in favor of the pro-United Nations resolution. THE UNITED NATIONS' TOP TEN DEBTORS Unpaid contributions to the United Nations now total $602 million.* 1988 assessment Debt to U.N. as a percentage in millions of U.N. budget United States 25.0% $466.9 South Africa 0.4 33.9 Brazil 1.4 17.9 Iran 0.6 12.1 Soviet Union 11.8 12.1 Argentina 0.6 6.3 Mexico 0.9 6.2 Israel 0.2 4.7 Poland 0.6 4.3 Rumania 0.2 4.0 * Does not include peacekeeping operational costs or contributions to the special U.N. agencies. (Source: United Nations)

Photo of Pres. Reagan meeting with U.N. Sec. Gen. Perez de Cuellar (NYT/Paul Hosefros)