The case of the assassination of John F. Kennedy is complicated, and it is unwise to go gaga over every bit of new information, taken in isolation. That is what the History Channel did in its reckless and now withdrawn feature accusing Lyndon Johnson of having authored the plot. And it is unfortunately also what Max Holland does in the Atlantic's June issue in reporting on the release of Johnson's 1967 telephone conversations related to the killing.

Holland focuses on a conversation held March 2, 1967, in which Texas Gov. John Connally alerted Johnson to information supposedly coming from the investigation then underway in New Orleans by district attorney Jim Garrison. Connally relates the claim "that Garrison has information that would prove that there were four assassination [teams] ... assassins in the United States, sent here by [Fidel] Castro, or Castro's people. [Sent] not by Castro himself, but by one of his lieutenants ... One of the teams was composed of Lee Harvey Oswald, this fella [Clay Shaw] that has just been arrested in New Orleans yesterday, and the [deceased] man [David] Ferrie, plus one other man. They were teams of four. And there were two other teams I know nothing about." What does Holland make of this? He begins with a kernel of truth: Castro surely had learned of CIA plots to assassinate him and overthrow his government. As Holland writes, these efforts began under President Eisenhower and continued into 1963 (when, as Holland does not relate, the Justice Department under Robert F. Kennedy made an effort to shut some of them down). Second, Holland ties Bobby Kennedy into the Castro assassination plots, as others have done, in one of the most curious passages in his article: "It is not known whether Johnson asked [Richard] Helms under whose direction the CIA had acted. If he did, Helms presumably said that Robert Kennedy 'personally managed the operation on the assassination of Castro.' (This is taken from what Helms told Secretary of State Henry Kissinger in 1975, after allegations of CIA wrongdoing began to surface in the press.) Then again, Johnson may not have bothered to ask. Edward Morgan had already told Drew Pearson about the former Attorney General's central role; it was common knowledge within the administration."

In this passage, conjecture is piled on conjecture. The effect is to bring forward a statement made by Helms in 1975, when Bobby Kennedy had been safely dead for seven years, to 1967, when he was still alive. If Helms had made such a claim in 1967, of course, LBJ could presumably have called Kennedy for his side of the story....

In trying to explain Johnson's motives for covering up a Castro plot, Holland evokes Johnson's loyalty to President Kennedy. He writes, "If the CIA's attempts to assassinate Castro had been known more or less contemporaneously with JFK's assassination, the Kennedy mystique would have been punctured." And so Johnson fell on his sword in 1968 partly to protect Bobby from questions about his activities that might have cast aspersions on his dead brother -- questions that in Johnson's conspiratorial mind had led to a revenge killing by a communist leader, who for unstated reasons Johnson also wanted to protect. And this even after Bobby's desertion from Johnson's cause? Even when Johnson might have found ways -- as he surely knew how to do -- to raise those questions while disguising his own role as their source?

The reasoning is tortured. It implies, among other things, that JFK may have been morally responsible for his own death -- or at least that his successor thought so. The tale is implausible. And it rests entirely on a chain of surmises. There is, in fact, no evidence for it at all.

It is extremely curious that the standards of history and evidence relating to the Kennedy assassination have sunk to the point where the History Channel can broadcast a scurrilous documentary implicating Johnson, while the Atlantic chooses to publish an account that leaves, at the very least, the heavy hint that Castro was involved.

Meanwhile, the many books that point to elements within the Mafia, the military and the CIA -- as indeed the conclusions of Cuban state security do -- remain beyond the pale. Strangely, they are not subject to review in the culture's polite journals. They are taboo. So far as Max Holland and the Atlantic are concerned, they do not appear to exist.

If I were a conspiracy theorist, I'd say that was a sign of a troubled conscience.