Israel rebuffed these demands, but at the same time it launched a third and even more comprehensive investigation. Headed by military jurist Col. Yeshayahu Yerushalmi, the commission delved into the question of the control-board markers, the pilots’ testimonies and the orders given to the torpedo boats. Yet, while critical of the same intelligence failures noted in the earlier reports, as well as the awkward command relationship between the air force and the navy, Yerushalmi’s findings were identical to those of his predecessors. “For all my regret that our forces were involved in an incident with a vessel belonging to a friendly state,” he wrote, “I have not discovered any deviation from the standard of reasonable conduct which would justify a court- martial.”⁴¹

The top-secret Yerushalmi report was conveyed to the Americans, who rejected it with the same mix of incredulity and indignation that had marked their responses to the previous reports. But the United States was holding its own investigations into the affair, beginning with the Navy Court of Inquiry held in Malta shortly after the attack. The hearings revealed basic contradictions in the testimonies of McGonagle and other officers regarding the length and sequence of the attack, and raised the possibility that, due to light winds, the flag might well not have been visible to Israeli pilots. Furthermore, Rear-Adm. Isaac C. Kidd, Jr., the presiding officer, found no evidence that the attack was in any way intentional, calling it “a case of mistaken identity.” Subsequent closed-door inquiries were conducted by the CIA, the NSA, the JCS, as well as by both houses of Congress. All reached the same conclusion: That the Israeli attack upon the USS Liberty had been the result of error, and nothing more.

Yet suspicions of Israel’s duplicity in the incident, even among high officials, lingered. As Rusk asserted many years later in his memoirs, “I didn’t believe them then, and I don’t believe them to this day.”⁴

The American and Israeli investigative reports go a long way toward disproving the charge that the Israelis maliciously opened fire on a ship they knew to be American. In the three decades prior to their declassification, however, numerous theories were posited to explain why Israel, engaged in war and internationally isolated, would willingly attack its only superpower ally. Now, with the aid of the recently released documents, it is possible to determine whether any of these hypotheses had a basis in fact. Among the more far-fetched theories that have been suggested is the possibility that the Liberty was attacked because it had learned of the Israeli execution of Egyptian POWs; or that it had picked up Israeli attempts to draw Jordan into the war so that Jerusalem might be brought under Israeli control.⁴³ But no document, American or Israeli, contains any reference to prisoner executions; neither are they mentioned in any Arabic source that has come to light to date.⁴⁴ By the same token, the Jordanian attack on Israel on June 5 and the fall of Jerusalem to Israeli forces on June 7 took place well before the Liberty’s arrival off the Gaza coast, and none of the documents now available in any way link the Liberty incident on June 8 to these events.

Far more serious has been the claim that the Israelis attacked the Liberty because it had been eavesdropping on Israel’s plans for capturing the Golan Heights. Thus Adm. Thomas Moorer, writing in the July-August 1997 issue of The Link magazine, has speculated that

Historian Donald Neff takes the supposition a step further, presenting it as fact:

Indeed, Neff goes so far as to posit that Israel actually delayed its attack on Syria until after the Liberty was neutralized.⁴⁶

The theory that the attack on the Liberty was motivated by a desire to conceal the impending Israeli attack on the Golan Heights is not, then, confined to the extremist fringe, but has made headway in important political and academic circles. In the past, refuting it was dependent largely on appeals to common sense, such as that made by Ernest Castle, the former U.S. naval attaché, in an interview with British television:

Common sense would also dictate that the Israelis, in the process of handily defeating three Arab armies, could have easily sunk a single, lightly armed ship if they had wanted to. In such a case, they would not have attacked the Liberty in broad daylight with clearly marked boats and planes—submarines could have done the job—nor would they have ultimately halted their fire and offered the ship assistance.

But it is no longer necessary to decide the argument on the basis of common sense alone. Like the other claims for Israel’s alleged motive in attacking the Liberty, the one linking the assault to the Golan Heights campaign cannot withstand the scrutiny of the newly declassified documents. These confirm that Israel made no attempt to hide its preparations for an offensive against Syria, and that the United States government, relying on regular diplomatic channels, remained fully apprised of them. Thus, on June 8, the American consulate in Jerusalem reported that Israel was retaliating for Syria’s bombardment of Israeli villages “in an apparent prelude to large-scale attack in effort to seize Heights overlooking border kibbutzim.” That same day, U.S. Ambassador Walworth Barbour in Tel Aviv reported that “I would not, repeat not, be surprised if the reported Israeli attack [on the Golan] does take place or has already done so,” and IDF Intelligence Chief Aharon Yariv told Harry McPherson, a senior White House aide who was visiting Israel at the time, that “there still remained the Syria problem and perhaps it would be necessary to give Syria a blow.”⁴⁸

Similarly, the United States National Archives contain no evidence to suggest that information obtained by the Liberty augmented Washington’s already detailed picture of events on the Golan front and of Israel’s intentions there. The Israeli records, for their part, reveal no fear whatsoever of American opposition to punishing Syria, but only of possible Soviet military intervention. (It was this fear that led Israel to delay its decision to capture the Golan until the morning of June 9.) Nor do they suggest that there was any danger of an American ultimatum. On the contrary, from his conversations with presidential advisor McGeorge Bundy and other administration officials, Foreign Minister Abba Eban understood that “official Washington would not be too aggrieved if Syria suffered some painful effects from the war that it had started....”⁴⁹

Once again, there is no indication in the archives that the Israelis were troubled by the Liberty, much less considered it worthy of attack. Indeed, there is no evidence that anyone in the Israeli government, or the IDF Chief of Staff, knew of the ship’s presence at all.⁵⁰