FIREWALL: The Iran-Contra Conspiracy and Cover-Up.<i> By Lawrence E. Walsh</i> .<i> W.W. Norton: 544 pp., $29.95</i>

Oliver North called him a “vindictive wretch.” To then-Senate Minority Leader Bob Dole, he was “totally out of control.” Sen. Orin Hatch (R-Utah) echoed his party’s preferred spin: Iran-Contra independent counsel Lawrence Walsh was “criminalizing policy differences.”

Through seven years of such daily political musket fire and occasional pundit-driven cannonry, Walsh remained largely silent, assuming--as he now admits, rather naively--that in Washington, the rule of law would eventually triumph over the rule of lips. “Firewall” is Walsh’s lengthy tale of how this failed to happen and how he--once a quintessential member of the Republican elite--is angry at such erstwhile political partners as North, Dole, Hatch and others.

Now 85, Walsh had a long and, by conventional standards, distinguished legal career behind him when he was tapped by old friends in Washington’s federal judiciary elite to investigate the Iran-Contra affair. When he accepted his appointment in December 1986, then-President Reagan and his longtime political associate, Atty. Gen. Edwin Meese, already had stumbled badly in offering contradictory, implausible accounts of how and why a weapons trade with Iran--then even more a pariah in the U.S. government’s eyes than it is today--had been conducted. The “diversion” of funds to the CIA-backed Contra rebels seeking to overthrow the government of Nicaragua at a time when Congress had explicitly forbidden such assistance had proved even harder to explain.

Several traditional Washington steps had been taken to quiet the affair. Two White House figures had been dismissed--North and his nominal superior, National Security Council chief John Poindexter. A quickly convened, inadequately staffed body--the Tower Commission--had been formed to look into the matter. And Congress was slowly revving up for its ultimately disastrous nationally broadcast hearings the following spring and summer. But it was evident early on to the political-legal community in Washington that firing a couple of fall guys, forming a dilatory commission and holding hearings would not make certain problems go away.

Specifically, there was prima facie evidence that laws had been broken. The Iran-Contra weapons transactions seemed to be in violation of both the National Security Act and the Arms Export and Control Act. The proceeds from these deals seemed to have been spent without congressional approval and in direct contravention of a congressional prohibition. If these things had been done, then people had conspired to do them. And if they had conspired to do them, it was pretty obvious that they’d lied about what they’d done.

Not even the Washington press corps, which had been largely somnolent about the nature and extent of the covert wars waged in Central America during the Reagan years and the simultaneous, petroleum-inspired shenanigans involving Iran, Iraq and Israel,was prepared to let this one go. Legal action had to be taken. And Meese had acted for too long as a barker in front of Reagan’s tent to investigate potential crimes with any credibility. So under the ever-changing guidelines of the independent counsel statutes, an outside lawyer had to be found.

Enter Lawrence Walsh, then in private practice in Oklahoma City but with 12 years of experience as a state and federal prosecutor (some of it, unfortunately, many decades behind him) and six years as a federal judge on his resume. Why did he accept--even welcome--the appointment? As he is with other personal matters, Walsh is reluctant to discuss his decision in “Firewall.” But one reads between the lines that Oklahoma City--his wife’s hometown--was not like New York, where he’d been a prosecutor and attorney. Washington was where the action was. Walsh recognized that potentially major action was imminent, because he believed with some in Congress that Reagan was “within range of impeachment” for his role in Iran-Contra.

The title of Walsh’s book refers to the means by which Reagan avoided this fate. A firewall was constructed by the president’s White House and congressional associates so that however high the flames of investigation and indictment might grow, they would stop short of singeing the Reagan presidency.

Given what Walsh accurately describes as the lack of political resources at his disposal, it is little wonder that the president’s men succeeded. “I had,” Walsh writes, “none of the standard ingredients of political capital in Washington--no elective office, no backing from a powerful constituency, no control over federal funds or regulations, and no access to decision makers. . . . My team and I could be crushed when the political forces of government, the national security community, and the courts collided.”

And collide they did. As Walsh, the very model of a conventional criminal prosecutor, attempted to construct a classic criminal ladder by assembling documentation, grand jury testimony, plea bargains and convictions, he was dogged at every step by noncooperation, obfuscation, dishonesty and political flack. His own naivete, he now realizes, was partly responsible; he “was acting like a government lawyer who could expect honest compliance by a government agency.” Not only did the White House, the CIA and the rest of the national security establishment stall when asked to produce important documents, but individuals--ranging from Defense Secretary Caspar Weinberger through then-Vice President George Bush--concealed potentially damaging material. No more Mr. Nice Guy, Walsh now realizes he should have subpoenaed the documents rather than just request them.

Ever the conscientious professional, Walsh recounts how he slogged on despite the slash-and-burn defense tactics of the White House and its minions. Thwarted by congressional grants of immunity to key witnesses, he managed, in one of the more bizarre legal proceedings in American history, to isolate his evidence from congressional probes in order to prosecute North and Poindexter. Unable to indict them and other Iran-Contra figures on theft and conspiracy charges because of stonewalling from the Bush White House, he proceeded to indict and convict eight individuals on “peripheral charges” of lying and obstruction of justice.

When some of those convictions, notably those of North and Poindexter, were reversed on manufactured grounds by Reagan-appointed conservative judges, he continued with the indictments of others. When others, including Weinberger, who lied about having important documentation of pertinent events and then pleaded ill health to avoid trial, were pardoned by then-lame duck President Bush in 1992, Walsh put his faith in the power of his final report. And, ultimately, in this book.

Knowing as we do the result of Walsh’s frustrated labors as we read “Firewall,” there is something anticlimactic in following his efforts. But there’s also something touchingly and revealingly old-fashioned about Walsh himself. “In my view,” he writes, “a president might occasionally use his power in furtherance of some questionable policy; but if he was caught, he had to tell the truth, and so did his subordinates.” Twenty-five years after Watergate, such a view seems oddly ahistorical.

Indeed, reading “Firewall” becomes frustrating as Walsh obeys the temporal and geographical constraints of both his prosecution’s mandate and the Iran-Contra congressional committee’s limited and limiting approach. This book is not an official government report; one wishes that Walsh had dared to take his story further. Surely his probe touched such areas as Israel’s dealings with Iran and the CIA’s role therein, and of drug and weapons transactions in Central America condoned or sponsored by characters in our shady intelligence agency. But there is no mention of them in “Firewall.” Walsh spent too much time and too much public treasure to limit himself just to this “simple, straightforward narrative of what happened.” He seems to have been in a position to tell us more than just what he thinks might have been proved beyond a reasonable doubt. But the same patrician reticence that we now know undermined his investigations undermines this account as well.

Walsh, unlike all of the other now abundant Iran-Contra memoir writers, is too wise to try to tell us that he’s nothing more than a frustrated representative of the forces of truth and justice. Mistakes that he acknowledges having made--”initial underestimation of the scope of my job; my consistent under-staffing; my reliance on document requests rather than subpoenas; my drastic narrowing of our early investigation”--all contributed to what he sees as something of a failure in his mission. As interesting as his recounting of this mission is, there still remains a firewall between what we know about Iran-Contra and what really happened. “Firewall” does little to tear it down.