On Jan. 5 the U.S. representative at the United Nations Security Council joined in a polemical assault on Israel at a vulnerable moment. He voted for an unbalanced resolution, which in effect condemned Israel's deportation of nine Palestinians suspected of masterminding many of the demonstrations on the West Bank. Some may see this as an isolated lapse in America's stance at the U.N., but in fact it is part of a pattern.

Principled opposition to the use of the Security Council as an anti-Israeli bludgeon has lapsed. Insistence on permanent, institutional reform of the U.N.'s management and decision-making processes has lapsed. Discriminating use of U.S. funds to support international organizations favorable to U.S. interests has lapsed. The hard-won capacity to push successfully for important U.S. initiatives has lapsed.

Do all these lapses add up to a collapse? Has the administration abandoned the principled, effective U.S. stance developed at the U.N. during the early Reagan years?

There is reason to be concerned that such a collapse is in progress. Officials at the State Department are eager to prove that the United States has relented from its past hard-line opposition to abuses and anti-American bias in the United Nations. Even before Congress completed work on the FY '88 spending bills, Deputy Secretary of State John Whitehead had decided to reopen the funding spigots for the U.N. in New York. He did so without regard for the effect it would have on organizations more critical to, and favorable toward, U.S. interests. These moves send a clear signal to the officials and delegates in New York: they can safely continue with business as usual. They will.

According to the authorization language recently passed by Congress, before turning over the $44 million balance of the U.S. contribution to the U.N. for 1987, the administration must certify that the organization has implemented the decision-making and administrative reforms adopted at the General Assembly in 1986 and made progress toward limiting abuses, particularly by the Soviet Union, of the U.N. system's personnel procedures. Third World delegates at the latest General Assembly session adamantly resisted implementation of the critical component of the reforms, which gave the United States and other major donors more say in decisions affecting the use of the U.N.'s resources. Instead, the assembly voted to enlarge the membership of the key program-budget committee, making it too unwieldy to be effective. Though the United States voted against the move, neither the State Department nor the U.S. mission at the U.N. did anything effective to oppose it.

Now a plan is being considered to issue the required certification based on the easily reversible personnel shuffling the U.N. has been doing for the past year. Officials at the U.S. mission joined in a post-General Assembly media boomlet characterizing these administrative moves as part of an era of resurgence for the U.N. They did so despite the fact that, according to preliminary tallies, the United States took its worst beating in years in the voting at the 42nd General Assembly. Even though the U.S. delegation took weaker stands (fewer U.S. "no" votes, more abstentions), even though it did not push hard for any potentially difficult U.S. proposals, even though it gave the U.N. $100 million before any results were in, the outcome indicates a significant decline in the number of states voting with the United States.

At this year's General Assembly not a single U.S.-initiated resolution met with any success. We seem to be returning to the days when U.S. leadership on a resolution meant automatic failure. Congress asked for effective action against the abuse of "secondment," a procedure that allows member states to place their nationals in U.N. positions on a temporary basis. (Some states abuse the procedure to guarantee continued control over their nationals. Roughly 90 percent of Soviet nationals at the U.N. serve on such terms.)This year the United States introduced a relatively mild resolution on the secondment issue. It alluded to the recommendation of the High Level Experts Group (the G-18) that secondment be limited to no more than 50 percent of any state's nationals in the U.N. Secretariat.

Even in this weak form, the initiative died in "informal consultations," without reaching the floor of the General Assembly's budget and management (fifth) committee. U.S. initiatives in the second and third committees (on capital formation and free elections respectively) met with similar fates. The only success registered at the assembly was the virtual absence of anti-U.S. name-calling in resolutions -- the effect of several years of firm insistence on a principled position.

The White House has announced that Ambassador Richard Williamson, formerly the U.S. representative to the U.N. Organizations in Vienna, is the president's choice to take over the international organizations bureau. With the right backing, Williamson has the ability and experience to preserve at least some part of the achievements of the early Reagan years. But high-level policy officials at the State Department, working with the U.S. mission in New York, are pushing for premature certification on U.N. reform. If they succeed, they will preempt Williamson's authority and further damage the administration's faded credibility on U.N. issues. Williamson may not be confirmed until well into February, by which time the damage could be irreversible.

Many who worked hard to restore America's influence in the U.N. are appalled by the abandonment of the firm, principled, energetic approach that made it possible to do so. One hope remains. U.N. experience features prominently on the re'sume' of Vice President George Bush. The U.S. resurgence at the U.N. did not take place during his tenure there, but he has an opportunity to step inand prevent complete surrender of the gains made in recent years. Whether as a sitting administration official or as a presidential candidate, Bush should make clear now that he is not prepared to abandon the fight to restore America's influence in international forums.

The writer, a resident scholar at the American Enterprise Institute, resigned as assistant secretary of state for international organization affairs last fall in part over the issue he discusses here.