Although Lt. Col. Oliver North repeatedly reminded the select committee on the Iran-contra affair that he is not a lawyer and has no legal training, that did not prevent him from embarking on lengthy legal lectures. And since committee members by and large ignored the colonel's curbstone opinions, many viewers may have been left with the erroneous view that there is some merit to his claims of legal authority for activities of the executive branch in violation of congressional mandates.

Among the most extraordinary of Col. North's claims was the contention that under the Supreme Court's decision in the landmark Curtiss-Wright Export case, the president -- and by the colonel's implication, the president's men -- can carry out policies contrary to legislation enacted by Congress. The Curtiss-Wright case says no such thing and, in fact, stands for the opposite.

Curtiss-Wright involved a prosecution of private individuals for violation of a presidential order, made pursuant to a congressional resolution barring arms sales to Bolivia. The defendants challenged the power of Congress to delegate that authority to the president.

The Supreme Court held that there had been no unlawful delegation of power, that when dealing with foreign affairs Congress could paint with a broad brush and delegate to the president "a degree of discretion and freedom from statutory restriction which would not be admissible were domestic affairs alone involved."

Further, the court declared, in words directly relevant to Col. North's claims, "It was not within the power of the President to repeal the Joint Resolution . . . Congress alone could do that."

Thus, it is not within the power of the president to repeal the Boland amendments, the Arms Control Export Act, the Hughes-Ryan Amendment, the Neutrality Act or the many other laws and regulations that Col. North and his White House associates regularly breached in their zeal to carry out secret policies in conflict with those legally enacted by the only legislative branch established under the U.S. Constitution. JOHN CONYERS JR. U.S. Representative (D-Mich.) Chairman, House Judiciary Subcommittee on Criminal Justice Washington