Princeton, N.J.

TWENTY years ago this week, Lt. Col. Oliver North testified for six days before a special joint House and Senate investigating committee. Permitted by the Democratic majority to appear in his bemedaled Marine uniform, and disastrously granted immunity, Colonel North freely admitted that he had shredded documents, lied to Congress and falsified official records.

Colonel North justified these crimes as necessary to protect two of the Reagan administration’s covert policies: defying a Congressional ban on aiding the anti-Sandinista contra insurgents in Nicaragua; and selling arms to Iran — officially classified as a terrorist state — in order to free American hostages in the Middle East.

Mixing bathos with belligerence, Colonel North played the incorruptible action hero facing down Washington politicians and lawyers. He also suggested that, under the Constitution, the president and not Congress held ultimate authority to direct foreign policy.

Most of the Congressional committee members, Republicans and Democrats alike, expressed shock at Colonel North’s testimony. And despite the surge in Colonel North’s personal popularity, he failed to sway other Americans on the underlying issues. Clear majorities in opinion polls said that Colonel North had gone too far in his covert operations, especially in helping the contras. Roughly half of those polled believed that he had acted as if he was above the law. Sixty percent said that Congress was more trustworthy than the Reagan White House on foreign relations.