In the first third of a speech that lasted more than 90 minutes, Colonel Qaddafi focused on what he called the inherent unfairness of the United Nations, which gives the five permanent members of the Security Council far more authority than the nations only in the General Assembly. This, Mr. Qaddafi said, was dictatorship, not democracy and, as such, “was terrorism itself.”

“We are not committed to obeying or adhering to resolutions by the Security Council in its composition right now,” he said, adding that the Security Council should be renamed the “Terror Council.” At one point, he even tore the edge of the founding charter of the United Nations he held in his hand, saying he agreed with the document’s preamble but nothing else.

He said the organization’s power dynamic should be reversed — to make the Security Council an instrument designed to “implement the will of the General Assembly.”

Wearing a traditional copper-colored outfit and a pin in the shape of Africa on his chest, Colonel Qaddafi gestured and glowered, with occasional reference to scrawled written notes, and at one point grabbed an audio device to check how his words were being translated. Ali Abdussalam Treki, the Libyan diplomat who now holds the rotating presidency of the General Assembly, introduced him as the “leader of the revolution, president of the African Union, King of Kings of Africa.”

An hour into his address, Colonel Qaddafi began calling for investigations into each of the major wars since the United Nations was founded: the Korean War, the war over the Suez Canal, the Vietnam War and the ongoing war in Iraq, which he called “the mother of all evils.”

The Afghan war, too, he said, should be investigated for possible prosecution. At times, Colonel Qaddafi veered into conspiracy, saying, for example, that the H1N1 influenza virus, also called swine flu, might be a military or corporate weapon that got out of a lab, and he intimated that an Israeli hand was behind the assassination of President John F. Kennedy.

The Israeli-Palestinian conflict, he said, should be solved by the creation of a single state, which Mr. Qaddafi called Isratine, but Mr. Qaddafi stressed it was wrong to infer that Arabs hate the Jews. “You are the ones who burned them, not us. You expelled them,” he said, referring apparently to European nations.

For Mr. Obama personally, however, he had only warm words, calling on the collected nations to welcome “our son” on the occasion of his first United Nations appearance. “We are content and happy if Obama can stay forever as the president of America,” he said, and added that he feared America would return to its old ways after the end of Mr. Obama’s term.