Responding to sharp attacks today in the Security Council, the United States said its air strikes against Libya were a necessary action "in exercise of the inherent right of self-defense" recognized by the U.N. Charter.

U.S. Ambassdor Vernon Walters, however, was the lone voice in support of Monday night's attack. The Soviet Union, Libya and other Third World nations denounced the raids and demanded that the council condemn them.

Unlike the debate two weeks ago, when American allies spoke up promptly on behalf of the U.S. position during the naval confrontation in the Gulf of Sidra, the western members of the council remained silent during two sessions held this morning and this afternoon. The council will continue its debate Wednesday morning.

Privately, a number of western diplomats and representatives of friendly Third World countries argued that the latest U.S. actions would have little impact on Libyan terrorist operations, and would strengthen Muammar Qaddafi's hand in the region by forcing his worst enemies to rally to his cause in public.

Walters, however, made the case that the air strikes were a proportionate response to "Libya's harsh policy of international terrorism." He said the strikes were ordered only "when quiet diplomacy, public condemnation, economic sanctions and demonstrations of military force failed to dissuade Qaddafi."

Walters detailed the evidence compiled by Washington that Libya was involved in the April 5 bombing of a West Berlin discotheque in which one American soldier was killed.

He added, "We have evidence that Libya is planning widespread attacks against Americans over the next several weeks in Europe, Africa, Latin America and the Middle East."

Referring to one specific plot, the American ambassador said, "At the time we acted, the Libyan People's Bureau in Vienna was in the process of plotting a terrorist operation against an unknown target on April 17."

Ten days ago, Walters said, a Libyan plot to attack the U.S. Embassy in Beirut "resulted in a near miss by a 107-mm rocket which exploded on launch."

Walters said that Libyan terrorism "threatens all members of the civilized world community," and that it is "hypocrisy to equate the answer to terrorism with terrorism." The Libyan attacks "are not simply the random use of violence, but concerted violence directed against the values, interests and democratic institutions of all freedom-loving states."

Libyan representative Rajab Azzarouk insisted that "the barbaric, savage raids by the U.S. were not in self-defense."

He privately circulated to council members a proposed draft resolution which would "resolutely condemn the act of armed aggression against Libya carried out by the United States," and would demand an end to such attacks.

The Soviet Union was among the harshest critics of the American action and warned that "such kinds of actions cannot fail to affect the relationship between the U.S.S.R. and the United States." If they continue, said Soviet representative Yuri V. Dubinin, "the Soviet Union will be forced to draw far-reaching conclusions."

Dubinin also called on the council to condemn the American air strikes and to demand that the U.S. "cease its attacks on Libya." The objective of the council, he said, must be to end the "overt threat to international peace and to prevent the situation from getting out of control."

The council session was convened at Libya's request, and is expected to last for several days.