A political tragedy of global dimensions seems certain in Panama, where a military dictator, Gen. Manuel Noriega, is fighting ruthlessly, almost insanely, to retain power. I feel personally involved.

A decade ago my wife and I sat for 14 hours with Panama's then-strong man, Gen. Omar Torrijos, and Panama's ambassador to Washington, Gabriel Lewis, talking about ways to resolve the Panama Canal dispute so as to honor Panama's sovereignty and at the same time protect U.S. security interests. Inadvertently, I became a conduit, by columns and TV reports, between Torrijos and the Carter administration, helping both sides to agreement.

Aside from the fact that Torrijos never served a meal during that long conversation, my wife and I remember his swearing ''on my mother's grave'' to return Panama to civilian, democratic government. But Torrijos soon died in an airplane crash that many Panamanians believe was murder.

Last week I sat again with Gabriel Lewis, who recently fled Panama with his wife in the car of the Costa Rican ambassador, even as Noriega's helicopter gunships hovered over Lewis' residence. Noriega had gotten his puppet legislative assembly to declare Lewis guilty of sedition, subversion and high treason for ''coordinating a conspiracy'' to oust Noriega and his figurehead president, Eric Delvalle.

Lewis became a ''traitor'' when he had the audacity to telephone Col. Bernardo Barrera, the head of G2, the intelligence agency, and ask for ''the humanitarian release'' of the men, women and children who had been jailed for waving white flags after Noriega imposed martial law and snuffed out freedom of speech and of the press on June 11.

The same day last week that I met with Lewis I received a telephone call from Aurelio Barria, the president of Panama's Chamber of Commerce and a leader of the Civic Crusade, which put thousands of Panamanians into the streets to protest Noriega's despotic rule. Barria told me that he had been arrested by plainclothes goons bearing submachine guns and was forced to undergo interrogation while naked. He was released after being told that his arrest was ''a mistake.'' Then the Noriega-controlled media printed a phony story that Barria had accused the arresters of sexually abusing him, and said Barria was ordered to appear for an examination to determine whether he was sexually abused ''before or after his arrest.''

Clearly, there are no human rights and there is no rule of law under Noriega and the ''Panama Defense Forces,'' which he has increased ominously from 6,000 to 20,000 men. Panamanians swear that Noriega is constantly under the influence of cocaine. A resolution by the U.S. Senate refers to charges that Noriega may be involved in drug trafficking, money laundering and other forms of corruption. It asks that Noriega and his military cronies ''relinquish all official and unofficial duties pending the outcome of an independent investigation.''

Remarkably, this resolution was sponsored by both Ted Kennedy and Jesse Helms, by Barbara Mikulski and Strom Thurmond.

Senators of every political stripe know that what is happening in Panama is more important than the uprising in South Korea.

The Reagan administration has at times played footsie with Noriega because Panama is host to some 9,000 U.S. military personnel, several important military installations and the Southern Command of the U.S. Armed Forces. But Washington faces a real challenge now, because there is evidence that in his desperation to hold power Noriega is seeking a conneciton with Nicaragua, Cuba and the Soviet Union.

Noriega is inviting conflicts that will shame the memory of Torrijos and bring grief to all of us who fought for a Panama Canal arrangement that we hoped would let Panamanians and Americans live forever as good neighbors.