Last week the buffoonery that passes for statecraft at the United Nations made New York's Mayor Edward Koch mad. Now, the mayor can be an amusing fellow, but when irked--and irked for good reason--he can be a genius. Heated to the boiling point by another of the United Nations' hallucinogenic resolutions, the mayor set out to make editorial changes on a city-owned wall across the street from the Noble Experiment. Then he invited the U.N. to depart New York.

The wall now bears an inscription from the Prophet Isaiah frequently heard during the U.N.'s winsome youth: "They shall beat their swords into plowshares . . ." Noting the U.N. as it is now in its years of seedy dissipation, the mayor would like to add references to "hypocrisy, immorality and cowardice"; he has poured over the Bible to find a suitable passage.

A sonority about beating swords into plowshares might have had some vague relevance to the U.N.'s activities in the 1950s, when empires were being broken up, embryonic nations established and conflicts arbitrated somewhat successfully. Unfortunately, the U.N.'s days of decency have passed.

Swords are not being transformed; rather, they are being modernized. There are missiles and satellites. There is that stupendous terrorism network that Claire Sterling talks about in her recent book. And there are those ghastly biological and chemical weapons, developed by the Soviets in violation of the 1925 Geneva Protocol on gas warfare and the 1972 biological weapons convention. These weapons are now being used by the Soviets and their clients in Afghanistan and in Southeast Asia.

On these momentous matters the U.N. remains quiescent. Instead, it is devoted to three great goals: embarrassing the United States, delegitimatizing Israel, and working some kind of exorcism on South Africa. This is the appalling condition of the Noble Experiment. Fetched by visions of macabre spectacle, last week I decided to see the place for myself.

In its most recent act of infamy, 86 nations--among them Libya, Iraq, Iran, Afghanistan, Laos, Vietnam and the Byelorussian Soviet Socialist Republic--had voted another hate--Israel resolution. This one urged all the nations of the world to isolate Israel for its annexation of the Golan Heights. Moreover, by declaring that Israel "is not a peace-loving nation," the resolution established grounds for Israel's expulsion. It also singled out the United States specifically for abuse. Imagine, the aforementioned nations passing judgment on Israel's credentials as a peace-loving nation! This, I had to see.

Accompanied by Kenneth Adelman, our jovial and unusually learned deputy permanent representative, I strolled through the softly lit halls, peeked into sleepy conference rooms, marveled at the talents of two hard-pressed bartenders as they attempted to quench the prodigious thirsts of the giants of world statecraft during their mid-afternoon happy hour. The interior of the U.N. puts one in mind of the urban campus of some third-rate state university: there are posters booming the current good causes (the PLO and SWAPO), seminar rooms sparsely attended, and what appear to be overaged foreign students loafing in the slightly grimy hallways. All acknowledged Adelman with various degrees of obsequiousness. All would delight in stopping to bend his ear. If he knew more than one-fifth of the waving, bowing statesmen, I should be surprised. American diplomats here are treated as the grand patrons, and so they are.

The United States pays some $1 billion of the U.N.'s budget, and is condignly reviled for its many kindnesses. Our interests are ambushed. Our allies, when in need, ostracized and frustrated. For my part, I care not a snort for South Africa, but Israel merely tries to survive in a sea of hostile and unreasoning instability. Were Israel to disappear tomorrow, as many U.N. members wish it would, the hatreds of the Middle East would continue: Arab against Arab, Moslem against Moslem. To blame Israel or the United States for these troubles is surrealistic.

Mayor Koch is in good form. The U.N. ought to pack up and depart. This forum of "peace-loving nations" has become a forum of hate and a source of mischief. The United States ought not to be its host. Let the U.N. move its headquarters to progressive Moscow; our FBI would be much relieved. And if, as the U.N. leadership declared last week, the General Assembly is such a boon to its host city, let them move to a needy Third World city. In such metropolises the world statesmen would have a lot more time to meditate on American hellishness, and they would grow more svelte and upright.