TIMES ARE HARD for Israeli diplomats serving at the United Nations. Their Arab counterparts have converted the halls and chambers of the organization into an ideological battlefield almost as intense as the real one back home. While the most flagrant acts of international illegality are silently ignored, a coalition of Arab, Communist, and Third World countries noisily churns out hundreds of anti-Israel resolutions in every U.N. forum. So the diplomats were probably not surprised to learn last week that the U.N. is scheduling a conference in Vienna this July to examine "an alleged alliance" between South Africa and the Jewish State.

Anything associated with Israel's existence--from her founding ideology of Zionism to the manner in which she carries out public works projects--tends to prove an acceptable target. The U.N. has voted to condemn Israel for achaeological digs in Jerusalem--digs proposed and defended by U.N. experts. Other U.N. organs have not gone uninfected by this venom; Arab delegates at a 1980 Women's Conference changed the agenda from women's rights in general to the status of Palestinian women under Israeli administration, perhaps fearing that their own countries would be criticized for denying women the right to vote. Not surprisingly, the gathering ended with a statement calling for the "eradication of the evils of Zionism."

The Israel-South Africa conference shows all the signs of continuing this pattern. Looking at various nations 'links to South Africa is, of course, an eminently worthwhile activity for the U.N. to pursue: South African delegates were booted from the General Assembly in 1981 for "not representing a majority of South Africans," and the apartheid regime has been the target of richly deserved economic and political sanctions since the early 1960s. But most nations have proved unwilling to pay more than lip service to sanctions, and more than $20 billion worth of goods quietly cross South Africa's borders every year.

But the time the delegates in Vienna spend scrutinizing Israel's role in this trade would be far better spent in checking the U.N.'s own figures. There, they will find that the nations that criticize South Africa the loudest are often those that profit most from covert trade with her. Statistics from the International Monetary Fund reveal that Israel is ranked as South Africa's 20th largest trading partner, accounting for 4 percent of her imports and exports. On the other hand, Black Africa, which officially maintains a total boycott of South Africa, has economy links with the apartheid regime amounting to almost $1 billion worth of goods each year--roughly eight times that of Israel. More startling is that some African nations hold direct investments in the white supremacist state; Israel, according to a recent New York Times article, has virtually none.

SOUTH AFRICA'S landlocked neighbors may have little choice but to deal with her. But that excuse cannot hold for all the nations above Israel on the list; some of the regime's best trading partners are oil-rich Nigeria and Zaire, both thousands of miles to the north. Most blatant of all is the hypocrisy of the Arab states which proposed the Vienna conference, which pump 400,000 barrels of oil a day into the apartheid economy. And the Daily Times of Nigeria reports that even armaments destined for Saudi Arabia and Iraq mysteriously find their way to South Africa. Kenyan newspapers regularly carry stories of Arab investments in South Africa, and their widespread purchase-of gold.

The attempt to condemn Israel for propping up a system of racial discrimination also loses some of its luster in view of the progress the sponsors have made on human rights in their own countries. Saudi Arabia recently expelled five Europeans and Americans for attempting to hold a Christian service in their home. This is not as astonishing as the reported persistence in Saudi Arabia of Black slavery, an institution legally abolished in the early 1950s.

But in the Orwellian world of the United Nations, illusion becomes reality by majority vote. Arab delegates will flock to the well-publicized summer meeting. For three days, self-righteous accusations will pollute Vienna's air and, in all likelihood, the meeting will conclude with yet another anti-Israel resolution. The Arab nations will have won a propaganda victory, and the United Nations will not have moved one step closer to ending apartheid.