Showdown in the UN over Israel

The United Nations runs the risk of being irreparably damaged by two leaders considered by many diplomats here to be ''desperados'' on the international scene: Libya's Muammar Qaddafi and Iran's Ayatollah Khomeini.

Monitor special correspondent Louis Wiznitzer reports that Qaddafi is expected to seek the expulsion of Israel from the General Assembly later this month and Khomeini may well join him, despite strong representations made by Islamic and Arab diplomats to the Libyans and Iranians.

The vote, expected Oct. 25, will be public. And since feelings against Israel run strong in the third world, it will be hard for many delegations to vote against such a move for fear of being seen as ''soft on Israel.'' If a majority of the General Assembly endorse the explusion, Israel would remain a member of the UN but be barred from participating in this year's General Assembly.

The United States - as made clear by Secretary of State George Shultz - would immediately walk out of the General Assembly and stop financing its 25-percent share of the UN budget. This would wreck the organization, in the opinion of most officials here. Even if the US later wanted to rejoin the UN, diplomats here say, Congress might make such backtracking very difficult, if not impossible. And without the US, the UN would lose much of its relevance and efficiency, they say.

Most Arab countries and the Palestine Liberation Organization realize that de facto expulsion of Israel would represent at best a Pyrrhic victory and would go against their own best interests. But no country seems to have any real influence on Qaddafi or Khomeini, who appear determined to push ahead out of ''spite,'' as one leading third-world diplomat put it.