ANNABA, ALGERIA, FEB. 7 -- The terror, Moammar Gadhafi explains in a softly rolling baritone, comes only in response to America's support for violence in other countries. You stop and I will stop, the Libyan asserts.

Nearly two years after American bombers sought to destroy his housing compound in Tripoli, Gadhafi declares in one breath that he is ready for a new live-and-let-live relationship with the United States, which he hopes will begin as soon as the presidency of Ronald Reagan ends.

But in the next breath, he vows to continue his support for the outlawed Irish Republican Army in its struggle "against British imperialism," intimates that he is gearing up for another round of fighting with the French in Chad and defends terrorist leader Abu Nidal as "a Palestinian fighting to liberate his country."

The man America most loves to hate is subdued, almost sullen as he leans forward in a red leather armchair and takes off the bulky vest he has been wearing atop his green flight suit.

His American visitors wonder if it is a bulletproof garment that he now feels secure enough to remove after 30 minutes of conversation, but the question is never resolved as he talks for another hour in an unusually concise and calm tone that betrays no sign of apprehension. Neither Gadhafi's features nor his reactions betray any trace of the illness or depression that American intelligence sources have told journalists he had suffered in the wake of the attack.

He is heavier, but his face is not puffy and he laughs when asked about reports that he constantly takes pills and other drugs. "I do not even drink coffee," is his retort.

What Gadhafi did display during the wide-ranging interview, conducted today in this coastal city 300 miles east of Algiers, was a continuing fascination with Reagan and with the United States, which he portrayed as forcing him into a "friendship" with the Soviet Union for which he showed little enthusiasm.

His comments also suggested that he is slowly coming to terms with Algerian President Chadli Bendjedid's effort to bring Libya into a loose regional grouping as a way of stopping Gadhafi's destabilization campaigns against his neighbors in North Africa. Gadhafi held talks here with Bendjedid yesterday.

"I personally would have signed it a long time ago," Gadhafi said of the friendship treaty arrangement that Bendjedid has offered the Libyan ruler as a substitute for the political union with Algeria for which Gadhafi has campaigned over the past year.

But, he continued, the decision to join the treaty, which currently links Tunisia, Mauritania and Algeria, is up to regional and municipal councils in Libya that are now debating the question and that will deliver their verdict by April 1.

He rejected concern voiced by the United States that Libya's joining the treaty would represent a lessening of the isolation the United States has sought to impose on Gadhafi.

"Libya has never been isolated, and it never will be isolated. The United States has no right to interfere in relations between Libya and other states," he said.

Gadhafi, who was interviewed by Katharine Graham, chairman of The Washington Post Co. and correspondents of The Washington Post and Newsweek, said that tensions between Tripoli and Washington have lessened in recent months after being on the edge of war for most of the Reagan administration.

He appeared to welcome this but attributed it solely to the failure of "all the American attempts to attack us, which were mad. Reagan lost a great deal out of this" and finally gave up, in Gadhafi's view.

Asked about Libyan involvement in supplying weapons to groups that carry out terrorist actions, Gadhafi did not directly deny such involvement but appeared to defend it on the grounds that it balanced U.S. intervention elsewhere:

"Why is Reagan involved with the contras in Nicaragua, with UNITA in Angola, with Afghanistan? This is the same question. Let's all agree that everyone concern himself only with things in his own borders."

But if Reagan "goes to Chad, then I come to Chad. If he interferes in Palestine then I will interfere in Ireland. If he comes to Angola, I go to Panama. . . . If he doesn't stop, we may go to Panama," he said.

He did later specifically deny having knowledge of Libyan involvement in shipping 125 tons of weapons to the IRA aboard a freighter intercepted on Oct. 30 by France. He also said that evidence now coming to light showed that Libya had nothing to do with the bombing of a West Berlin discotheque that prompted the April 16, 1986, U.S. raid against Tripoli.

Asserting that Americans "definitely must have learned some lessons from the Reagan presidency," he said that he expected Libyan-U.S. relations to improve after the November elections.

Asked if he could intervene to help free American and other hostages held in Lebanon, Gadhafi condemned the taking of captives for any reason. But, he said, Americans had to understand that "they will be the price" paid for U.S. policy in the Middle East.

"Americans for their own security should get out of the Arab world," he said in a matter-of-fact manner. "None of us can control the reactions of individuals against Americans because of their policies, because of their bombing," he said without sounding threatening.

On Chad, where Gadhafi's troops suffered a serious defeat last year at the hands of the forces of Chadian leader Hissene Habre, the Libyan said he did not view this outcome "as the final result. It is a temporary result."

He declined to answer directly when asked if he would submit a dispute over the Libyan-Chadian border to the International Court of Justice as has been suggested by France, Habre's principal military backer.