UNLIKE Sherlock Holmes, who solved a case when a dog didn't bark, George Bush has a dog that refuses to stop barking: persistent allegations that he has not told the truth about his role in the Iran-contra affair.
Since reports of illegal arms sales to Iran first broke in 1986, Mr. Bush, who was then vice president, has insisted that he was largely uninformed and outside the circle of Reagan administration decisionmakers who used arms as barter to win the release of American hostages held by pro-Iranian groups in Lebanon.
But information turned up by congressional investigators and a special prosecutor commissioned by the Justice Department suggests, though not conclusively, that Bush may well have been an informed and influential advocate of the plan that earned money later used to fund a Nicaraguan rebel group.
Pollsters say the issue ranks low among concerns cited by American voters. But it has arguably weakened Bush's appeal on the issue of trust and has provided a foil for Democratic challenger Bill Clinton to divert attention from his own questionable record on the draft.
Recent Louis Harris polls indicate that less than half of Americans believe Bush and Clinton are telling the whole truth on Iran-contra and the draft, respectively.
"They both have some negatives and they both have some positives, and our reading is that they offset each other to a certain extent," says David Krane, executive vice president of Louis Harris and Associates, a New York polling organization.
The Iran-contra affair began in 1985 when Israel, with US permission, secretly shipped 504 US-made TOW antitank missiles to Iran to win the release of Rev. Benjamin Weir, one of five US hostages in Lebanon. Five other shipments of arms and spare parts followed.
The sales violated US laws governing arms exports and covert CIA operations as well as the US's own arms embargo on Iran, then at war with Iraq.
In a 1987 campaign biography, Bush said he had been left in the dark because the Iran-contra operation was "compartmentalized, like pieces in a puzzle." He concluded he had been "deliberately excluded from key meetings involving details...."
But White House records obtained by Congress and the special prosecutor, Lawrence Walsh, indicate that Bush attended as many as three dozen meetings where the issue was one of the principal topics of discussion.
Bush told Washington Post columnist David Broder that after he learned of the matter, he reluctantly went along, since neither Defense Secretary Caspar Weinberger nor Secretary of State George Shultz had objected to the arms-for-hostages swap. A strong contradiction
But other documents obtained by investigators indicate that these Cabinet officials had expressed strong opposition to the arrangement at a White House meeting that Bush had attended.
The day after the Broder article appeared, Mr. Weinberger called Mr. Shultz to express dismay at Bush's comments. "It's on the record. Why did he say that?," Weinberger is quoted as saying in a recounting of the conversation dictated by Shultz to an aide.
A State Department record of a January 1986 White House meeting with President Reagan indicates that of seven senior administration officials, including Bush, "Shultz and Weinberger argue[d] strongly against the Iran proposal, but everyone else favors going forward."
One month later national security adviser John Poindexter told a White House colleague that the "president and vice president are solid in taking the position that we have to try."
According to notes taken by one of his own aides, Bush was also briefed on the details of the Israeli arms shipments by an Israeli official, Amiram Nir, in a July 1986 meeting in Jerusalem.
The contents of Mr. Nir's own account of the meeting, disclosed last week on ABC's "Nightline," also indicates that Nir described the arms-hostages link to Bush.
Bush has not been accused of illegal behavior. And there is no clear evidence that he was aware of the diversion of proceeds from the arms sales to the Nicaraguan contras at a time when aid to the Contras was banned by Congress. Instead, the issue is whether Bush was fully aware of and supported the arms-hostage and contra diversion operations.
Last week former Reagan national security aide Howard Teicher disclosed that he had briefed Bush in detail about the arms-for-hostages deal in the spring of 1986.
And in a book on the Iran-contra affair released last month, former Pentagon official Richard Secord recounts meeting with Amiram Nir shortly after Nir's meeting in Jerusalem with Bush. Mr. Secord says Nir told him that Bush was knowledgeable on the subject of the arms-for-hostages deal.
Secord says Bush then persuaded Reagan to resume arms shipments, this time Hawk missile parts, in an effort to secure the release of the hostages on a one-shipment-one hostage basis.
Secord, then an Air Force major general and a close associate of National Security Council official Oliver North, the main playmaker in the Iran-contra affair, later pleaded guilty to making false statements to investigators.
Mr. Walsh, the special prosecutor, ended a five-year, $32 million inquiry into the Iran-contra scandal last month. The investigation led to the indictment of 11 officials, eight of whom were convicted or pleaded guilty. Two convictions, Poindexter's and North's, were later overturned.
Cases are now pending against Weinberger, charged with perjuring himself before a Congressional investigating committee, and two senior CIA officials, Duane Clarridge and Clair George, who is facing a retrial. No conclusive proof
The investigation, which was branded a witch hunt by detractors, failed to turn up conclusive proof that either Reagan or Bush was an active participant in the decisionmaking process or that there was a conspiracy to conceal Reagan's knowledge of the Iran-contra matter.
As for the salience of the issue in the current election, voters are preoccupied with other issues, pollsters say.