Lessons from the 1967 Israeli attack on the USS Liberty.

A new chapter in naval warfare is being written as Britain and Argentina spar over control of the Falkland Islands. But this weekend, in Washington, a group of American veterans are commemorating one of the most distressful incidents in American naval history.

The incident is the sinking of the USS Liberty, which took place on June 8, 1967. The event, still somewhat shrouded in secrecy, raised the question of whether the state of Israel willfully sank a United States military vessel.

From the incident, US military planners learned some unpleasant lessons about the shortcomings of the American military communications system. They also learned the tragically unpredictable consequences of hostilities in the Middle East - specifically, how a conflict in that volatile region can quickly involve the United States.

Survivors of the US electronic intelligence-gathering ship - which Israel attacked with torpedoes, napalm, rockets, cannon, and machine-gun fire during the ''six-day war'' between Israel and Egypt - are determined to see that the lessons aren't lost on the US. Many of of those who were aboard the USS Liberty are expected at a Washington reunion this weekend (June 5-6). The gathering will doubtless rekindle the controversy that surrounded the sinking of the Liberty a decade and a half ago.

''There's been very little contact among the crew for almost 15 years,'' says reunion organizer James M. Ennes Jr.

Mr. Ennes, who was a lieutenant and cryptography specialist aboard the vessel , has been one of the chief critics of the US government's handling of the incident. He claimed in a 1979 book ''Assault on the Liberty'' that the attack on the ship was a premeditated act, rather than a case of mistaken identity - as the Israelis have claimed.

Israel maintains that its assault on the Liberty was a tragic error, for which it rapidly and effusively apologized. It paid a total of $3,323,500 to the families of those killed and $3,452,275 to those who were injured. To compensate for the damage to the Liberty, which never returned to duty, Israel agreed to pay three annual installments of $2 million, the last of which is due on Jan. 15 , 1983.

Calling the attack ''an honest mistake in the heat of war,'' one Israeli source here claims it resulted from a ''breakdown in communications'' between the Israeli reconnaissance and fighter aircraft. ''Nothing was worth sinking a US ship,'' says the source, who says that Ennes has failed to show convincingly why the destruction of the Liberty would have been to Israel's advantage.

Moreover, Israeli sources claim that right-wing elements have seized upon the incident to whip up anti-Israeli sentiment in the US. As recently as this year, the Anti-Defamation League was giving space in its newsletter, ''Insight,'' to rebut criticism of Israel's role in the incident.

Still, interest in the sinking of the Liberty is periodically revived - notably, by Ennes and other survivors, who insist that the complete story has yet to be told. They have won a number of converts over the years. Retired Adm. Thomas H. Moorer, who became Chief of Naval Operations some three weeks after the Liberty was attacked and who served as chairman of the Joint Chiefs of Staff (JCS) from 1970-74, is to be the keynote speaker at the reunion banquet. He has long insisted the attack ''could not possibly have been a case of mistaken identity.''

''The ship was savagely strafed and fired upon as well as torpedoed in good visibility while she was flying the American flag,'' he has declared. Altogether , 34 men were killed and 171 wounded in the Israeli attack.

The USS Liberty arrived on station off the Gaza Strip on June 8, 1967, after 16 days' steaming from Abidjan, the capital of Ivory Coast and a port call at Rota, Spain. She had been ordered to the eastern Mediterranean by the JCS to perform what Ennes has described as ''a general listening mission.''

Here, by monitoring the myriad radio signals, the ship was presumably able, initially at least, to track the course of the furious fighting onshore. But the vessel also attracted the attention of Israel's military commanders.

Ennes recounts that Israel kept the Liberty under surveillance for six hours. Photo-reconnaissance aircraft buzzed the vessel 13 times, he claims, and says that Mirage jets then rocketed and machine-gunned it. Slower Mystere aircraft then napalmed the Liberty's funnel, gun mounts, bridge, and superstructure, he claims. Finally, he says, three motor torpedo boats raced in to deliver the final blow to the blazing vessel.

Two torpedoes missed, but a third smacked into the Liberty amidships, tearing a 40-foot hole in her side.

The Israeli government says it never has knowingly attacked any ship of an ally, especially one flying the American flag. It claims that the first time it realized the enormity of the mistake was when survivors were picked up in lifeboats and informed the Israeli crew that they had torpedoed an American ship.

In a 42-page report submitted to Adm. Thomas Hayward, US Chief of Naval Operations, the commander in chief of the Israeli Navy, Rear Adm. Zeev Almog, states that after thorough investigation, there could be no doubt that the attack on the Liberty came about as a result of ''innocent error'' by the forces that operated on the spot and by the headquarters that supervised them.''

Incidents of this kind do occur in wartime,'' said Rear Admiral Almog.

An Israeli Embassy official in Washington pointed out that in past Middle East wars, Israeli ground, tank, and air force units had, on a number of occasions, as a result of communications problems, accidentally attacked their own men, tanks, and planes. The official also stated that the Liberty was operating, prior to the 1967 attack, in an area considered a battle zone and at a time when Egyptian vessels were shelling the El-Arish coast.

But many survivors doubt the Israeli version of events. What particularly rankles them is the Israeli's private assertion - repeated in the pages of Insight - that the Liberty refused to identify itself to the Israeli torpedo boats. The Insight account suggested that this refusal to identify (through the use of light signals) ''contribut(ed) to the torpedoing of the ship.''

Recently, Ennes obtained, through a Freedom of Information Act request, a copy of a secret Navy cable that casts doubt on that assertion. In it, Navy Rear Admiral Isaac C. Kidd states that the commanding officer and signalman on the Liberty flatly deny they ever received a request for identification from the Israeli torpedo boats. They were adamant in denying that they ever refused to identify the Liberty. Rear Admiral Kidd concluded the cable with the observation , ''I am convinced these men know what they are talking about.''

Why would the Israelis launch a deliberate attack against a US vessel? Ennes, who was wounded in the attack, theorizes that Israel attacked the electronic intelligence-collection vessel because it was in a position to detect the invasion of Syria. The Israeli government was acutely aware of President Johnson's warning to Foreign Minister Abba Eban ''that he would support Israel only in self-defense, not in attacks against her neighbors,'' he writes. ''Could Israel put troops in Syria without being seen as an aggressor? Probably not. Not with USS Liberty so close to shore and presumably listening. Liberty would have to go.'' He suggests that the late Brig. Gen. David Elazar waited until the Liberty was ''dispatched'' before he seized the Golan Heights.

That conclusion is, of course, debatable. But the Liberty attack, whatever the motivations, pointed up major shortcomings in the US military communications system. Apparently, several attempts were made to pull the Liberty out of harm's way before disaster struck. But the Pentagon was apparently unable to communicate with the ship.

A priority message from the JCS ordering the vessel back 20 miles from the Egyptian coast was delayed and misrouted, according to a 1971 report of the House Armed Services Investigating Subcommittee. Subsequent follow-up messages were also mishandled, according to the report.

Ennes himself acknowledges that one of the key foul-ups in the communications breakdown came on the Liberty itself. The ship sent a message to the Sixth Fleet commander immediately after the attack began, then followed up quickly with another message expressing greater urgency. Somewhere in the communications chain, this second message was given a higher priority and actually reached allied command headquarters first. But by this time, the Liberty crew already had destroyed its ''authenticator'' charts, which meant that it could not prove to fleet headquarters that the message in fact was coming from the Liberty. Ennes acknowledges that these crucial communications charts should be the last thing a ship's crew destroys before being sunk or captured, and that because of this mistake air cover and other help from the fleet probably was delayed. ''In the panic of a time like that,'' he says, ''every possible goof up that could have occurred, happened that day.

Still, to this day former chief petty officer Stan White is bitter about the recall order. ''I've never been able to understand why they didn't come down and fly over anyway and see if we still existed,'' he says. ''If they were in the air, a pass over would have done a lot for morale.''

In the subcommittee's view, ''The circumstances surrounding the misrouting, loss and delays of those messages constitute one of the most incredible failures of communications in the history of the Department of Defense.''

Dean Rusk, who was secretary of state at the time of the Liberty attack, has written, ''I hope that a great deal has been done to straighten such problems out . . . effective communication would probably have prevented the attack on the Liberty in the first place.''

Today, the Navy seems acutely aware of the need to communicate with the far-flung American fleet. A sophisticated command, communications, and control system (dubbed, in military lingo, ''C cubed'') is one of the big-ticket items in the Pentagon's planned multibillion dollar defense buildup.

Questions have also been raised about the Navy's response once the vessel waa hit. Two US aircraft carriers - the Saratoga and the America - were some 400 miles away. But they were slow to dispatch planes to aid the Liberty, and some of the aircraft were recalled before reaching the stricken vessel. Some critics suggest that the recall was ordered to avoid a confrontation with Israeli fighter jets. Others attribute the slow and indefinite response to the general confusion that existed in the wake of the attack. (See accompanying story.)

The US Navy convened a court of inquiry to investigate the incident, which found that ''there are no available indications that the attack was intended against a US ship.'' The board concluded that the incident had stemmed from ''a mistake in identity.'' The US accepted Tel Aviv's apology.

But the board's findings are hotly disputed. ''Our government repeated Israel's claim that the ship was mistaken for the Egyptian freighter El Quseir, but failed to note that El Quseir was a 40-year-old cattle boat, then moored at Alexandria, in poor shape, soon to be sold for scrap, probably incapable of leaving her pier, and a most improbable candidate for a Liberty look-alike,'' says Ennes.

He insists that the US government covered up the truth about the incident to avoid rupturing relations with Israel. Others, including some former top US officials, share at least some of his doubts that the incident was an accident. In a 1978 letter to Ennes, George Christian - President Johnson's former press secretary - wrote ''there was considerable skepticism in the White House that the attack was accidental.'' In later years, Christian says, he became convinced an ''accident of this magnitude was too much to swallow.''

Even now, many American officials are tight-lipped about the incident. A former senior US intelligence official says only, ''This is one I really don't want to handle. This is a loser in every direction. You get in a crunch between the Israeli lobby and the rest of the world if you start commenting on this thing.''

The incident undoubtedly provoked consternation at the highest levels of the US government, however. After the Liberty's plight was learned, a number of top officials were summoned to an emergency meeting in the White House Situation Room. One of them was Dean Rusk, the former US Secretary of State.

Last September, Mr. Rusk told Ennes he believed the assault on the ship ''was and remains a genuine outrage.'' He said he still did not know ''at what level'' in the Israeli government it was launched, ''but I am convinced that it was not trigger-happy local commanders.'' Still, Mr. Rusk says there was serious doubt ''whether that episode should have blown into a major confrontation between Israel and the United States.''

''Those who carry the ultimate responsibility . . . know that there are times when one has to pick up the pieces and not let everything fall apart because of an occurrence of this sort,'' says Mr. Rusk.

For many officials, the incident has faded into history. A Pentagon admiral, asked to comment on the Navy's version of the incident, said, ''You're catching me cold. . . . The lessons we're learning have to do with the Falklands crisis, and we're not really focusing back on the Liberty.''Still, the Navy learned important lessons from the Liberty episode. The Navy no longer uses small, essentially unarmed communications ships to do its spying. That practice halted after the Pueblo was captured by the North Koreans in 1968. This work now is done by destroyers, like the one that has been hovering off the coast of El Salvador and Nicaragua for the past few months - ships with their own defenses.