Ghassan Tueni, who represents a Lebanese government that is still in the process of formation, interrupted the flow of rhetoric at a special General Assembly session on disarmament today to inject a personal plea on behalf of "a small nation" that "was allowed to be martyred and crucified."

The 56-year-old former newspaper editor, speaking on his own rather than on instructions from Beirut, launched his eloquent appeal with scathing sarcasm by saying:

"The representative of Lebanon will certainly be understood and, I trust, excused if today he has no words on universal disarmament save the pious prayer that it should happen soon enough for his country to survive.

"The atomic holocaust of tomorrow becomes a problematic danger, remote and almost unreal to those who are living an actual holocaust."

Tueni, who has served as Lebanon's ambassador to the United Nations since 1977, blamed the Syrians and the PLO as well as the Israelis for turning Lebanon into "the arena where friends and foes alike find it convenient to wage their wars."

In a reference to the Palestinian presence, he said that "Lebanon should never again allow its liberty to be taken hostage by those to whom it was extended."

"There are many," he said, "who are now proposing to redraw our map, rewrite our constitution and even renegotiate, on our behalf, our national compact the division of governmental posts among the many Lebanese ethnic groups . To all of them, friends and foes alike, may Lebanon say that its future shall be only what the Lebanese, and the Lebanese alone, decide for themselves."

Although Lebanon still has "reservations" about PLO military activities in the country, Tueni insisted that it will continue to support the Palestinians' right to a national state "in their own homeland."

Tueni noted that Lebanon had informed the Arab League more than a year ago of its determination to "release the Arab Deterrent Forces from the role they now assume in Lebanon"--in other words, to seek withdrawal of Syrian troops. But he also rejected Israel's claim that its troop withdrawal be conditioned on a Syrian pullout and creation of a buffer zone in southern Lebanon.

"We know that U.N. resolutions are not solutions. We know how shattered is the authority of the Security Council but we also know the value of such an instrument of international law the council resolution adopted on June 6 , which clearly and unequivocally establishes the criteria of Israeli withdrawal: that it should be both immediate and unconditional."

Turning to the U.N. peace-keeping force in southern Lebanon, Tueni asked: "Are the small nations entitled to expect that peace-keeping forces should be enabled to defend them against aggression?

"To us in Lebanon, this is a question of great and grave urgency. Within two months when the U.N. peace force authorization expires , my government will have to make an existential, not an intellectual, choice.

"Do we need a U.N. force? If we do, what U.N. force can credibly confirm the withdrawal of an invader and assist us in restoring our sovereignty over all of our territory?"

Tueni also criticized the proposal for a nuclear-free zone in the Middle East made to the Assembly on Friday by Israeli Prime Minister Menachem Begin.

Before outlawing nuclear weapons, he said, "let us use no cluster bombs," a weapon Lebanon has charged Israel with using during the invasion of Lebanon.

Then Tueni openly recognized the danger of permitting "terrorists" to obtain atomic weapons--a statement of unprecedented frankness for any diplomat.

"Need one remind this assembly," he said, "that the atomic option now available in the Middle East to Israel alone may one day become a commodity of international terrorism? Nuclear gangsterism, as it is called, today a feature of political fiction, should not be allowed to become, tomorrow, the possible and frightening reality of a new radicalism created by frustration."

He concluded by saying:

"My country, now a martyr of both war and peace, appeals to you all. Let us not allow this assembly to be diverted by abstract testimonials for peace and no less abstract analyses of the causes of war."