President Reagan would exorcise the Iran-contra affair by a few strokes of his own pen. No laws having been busted so far as he can see, none need fixing, or so he says. He would tighten up procedures for ''covert-action operations'' -- reporting requirements within the administration, timely notice to congressional leaders and the like -- by executive order. ''Maximum consultation'' with Congress will be the rule. But to ''safeguard a nation'' the commander in chief must have a little running room.

The fine print leaps out in boldface: ''Except in cases of extreme emergency,'' he says at one point. And again: ''in all but the most exceptional circumstances.'' He does not say whether he would consider the safety of hostages or the burning needs of Nicaraguan ''freedom fighters'' exceptional. If he sees any larger constitutional concerns over the proper separation of powers that lies at the heart of the Iran-contra controversy, he shows no sign of it.

For a second opinion -- by way of joining what promises to be a lively congressional debate over how to right the Iran-contra wrongs -- I commend to you Clark Clifford, a fixture in these parts as a prestigious lawyer and longtime student and practitioner of government.

Clifford, it should be noted, speaks as an expert witness for the defense of the executive branch. That's where his experience has largely been: as a White House aide, the chairman of an intelligence review board and secretary of defense. It is much on his mind to ''preserve the president's independence to run the executive branch.'' But presidential abuse of power is also much on his mind. So he would seek to protect the powers of the presidency by strengthening statutory deterrence against their misuse by willful or lawless presidents, or out-of-control subordinates.

Clifford has no doubt that at least five laws were broken in the course of the Iran-contra dealings and double-dealings. His list includes the Boland Amendment's restriction on aid to the Nicaraguan contras; assorted requirements for ''timely'' notification of covert activities to congressional intelligence committees; provisions of two statutes governing the sale or transfer of American military equipment to foreign countries. ''If these laws had been obeyed,'' Clifford argues, ''they would have prevented this scandal.''

But it apparently did not occur to Congress, Clifford continues, that the executive would so carelessly flout the congressional will. So Clifford would introduce stiff penalties. He illustrates his purpose with a flight of imagination: ''I can see Ollie North in a meeting. Somebody makes a suggestion. Somebody else says that would violate such and such a law. Ollie asks, 'What is the penalty?' The guy says there is no penalty. And Ollie says, 'Please don't interrupt me.' '' A penalty, Clifford surmises, just might have given Ollie pause.

Clifford would discourage crippling, decompartmentalized foreign-policy making by strengthening the National Security Council, whose full members now include only the president, the vice president and the secretaries of state and defense. He would promote to full membership the chairman of the Joint Chiefs and the CIA director, who now serve only as advisers. He would add the secretary of the Treasury as a full member, on the theory that he would be useful when public funds are at issue. He thinks the Joint Chiefs could have exercised restraint had they not been largely cut out of Iran-contra deliberations.

Clifford would implant in the White House a small, permanent staff of professional civil servants available for their nonpartisan, nonideological expertise and longer term perspective. He would add a permanent assistant staff director, also serving from one administration to the next, as another element of institutional continuity.

Clifford would write some of Reagan's ''new executive procedures'' into law, add others and skip the fine print. Fear of leaks, he insists, ''has not sufficient substance or proof behind it to warrant the argument.'' A strong and sensible president ought to encourage cautionary words from congressional old-timers with longer memories than his own.

An excessive congressional invasion of presidential prerogatives? No more so, in principle, than the passage of the original National Security Act. That was a joint executive-congressional collaboration, which Clifford helped draft. As we have seen all too vividly, presidents can make as much or as little of the established machinery as they please. Clifford is suggesting reforms that a wise president ought to propose. Beyond that he is advancing nothing more radical than an argument that the laws should be obeyed.

His prescriptions look well beyond the Reagan presidency and proceed from the elementary proposition that we are a government of laws, not men. Reagan, on the contrary, would ask Congress in the wake of the Iran-contra revelations to accept on faith his own necessarily short-lived reforms by his own executive decree. Recent history should leave us in little doubt as to which is the safer, sounder approach.