ABU NIDAL left a calling card last fall in an interview with the German magazine Der Spiegel: "I can assure you of one thing," he said. "If we have the chance to inflict the slightest harm to Americans, we will not hesitate to do it. In the months and years to come, the Americans will think of us."

Americans may indeed be thinking of Abu Nidal following the events of last week in the Gulf of Sidra. His real name is Sabri Khalil al-Banna, and he is one of those on whom Libyan leader Muammar Qaddafi will most likely depend to carry out his campaign to attack American interests. It is clear that the Libyans are supporting Abu Nidal, and he is linked to last December's bloody attacks at the Rome and Vienna airports, only the most recent example of the mayhem that he has made his life's work.

In the wake of last week's events in the Gulf of Sidra and Qaddafi's threats of retaliation, it might be useful to take a closer look at Abu Nidal, the states that support him, and the environment in which he operates.

Here is a snapshot of the man who describes himself as America's enemy: His politics are those of revenge and revolution on a grand scale. He seeks through terror a retributive and perfect justice that can never be achieved. He moves through a shadowy inter-connected world of international and Arab terrorist networks that have given him a mystique larger than life. And yet through all of this there is something very ordinary, small and marginal about him -- something that seems to reinforce the fact that terror, no matter how brutal, is only a symptom of a failed cause and of the frustrations of a desperate man.

Perhaps even more frightening than the man himself is his relationship to those Arab regimes willing to tolerate his excesses. In a world where assassinations and violence have become legitimate tools of political struggle, Abu Nidal and those like him provide important services in the never-ending fight for influence and power. He is not simply a product of the Arab-Israeli conflict but of an intra-Arab struggle in which ideology is subordinated to regime survival and personal vendetta. How else can we explain that a man who in 1976 tried to kill the Syrian foreign minister could be operating out of Damascus seven years later?

Who is this elusive figure and what is the nature of the environment in which he operates? Is he simply the hired gun of state-sponsored terrorism, or is he the genuine revolutionary he claims to be?

One of the most frustrating aspects of dealing with Abu Nidal is that so little is known about him. Even in the murky subterranean world of international terrorism, he is a mystery. Despite two recent interviews, rumors still abound that he is dead or incapacitated and that his operations are run by committee. In a recent interview, Abu Nidal claimed that he had undergone plastic surgery. His interviewers usually ask him for some proof of his identity and wonder themselves whether he is who he claims to be. During one interview, Abu Nidal reportedly ripped open his shirt to show an inquisitive journalist scars from a much rumored heart operation.

His method of operation only enhances his image as a secretive shadowy force likely to appear anywhere at any time. The entire Abu Nidal organization is tightly compartmentalized and may not number more than a few hundred. The structure of the organization further obscures the links between operations and the master command. Capitalizing on the shadowy terrorist network in Europe and the Middle East, Abu Nidal further covers his tracks. Thus, in the Rome and Vienna operations, the terrorists could have been trained in Lebanon, acquired Libyan confiscated Tunisian passports, and obtained weapons in Europe.

The same difficulties apply to analyzing his recruiting style. Many of his recruits are probably young Palestinians, with varying levels of educations and places of origin. Abu Nidal can draw from disillusioned and radicalized Palestinian refugees in camps and shantytowns from Beirut to Amman. He can also use his European connections to recruit from more sophisticated Palestinian students on the continent. In traditional Middle Eastern style, he may also make effective use of an extended network of family relations and friends. According to Yossi Melman, an Israeli journalist who has published an account of Abu Nidal, the attempted assassination of the Israeli ambassador to Britain may have involved one of Abu Nidal's cousins.

What we do know about Abu Nidal's early years suggests unremarkable origins. Born in Jaffa, Palestine in the late 1930s to an affluent family, he attended French and Islamic schools before the outbreak of the 1948 Arab-Israeli war. Here accounts of his life vary significantly. Melman claims that his family moved first to Nablus. Because of the family's declining fortunes, he attended a government school and later went to Cairo University to study engineering. Afterwards he worked for a time in Saudi Arabia.

In a 1985 interview, on the other hand, Abu Nidal claims that his family moved first to Gaza as refugees where he was recruited by ARAMCO to work in Saudi Arabia. Here he claims he was arrested, tortured, and expelled from the country. This account, however, would have been far more marketable in revolutionary circles as Abu Nidal set out to validate his credentials as a militant Palestinian nationalist. It also presents an image of a young, educated, middle-class Palestinian -- disillusioned with the passivity of his parents generation and eager to deny his middle-class roots in order to pursue the struggle to "liberate Palestine."

By the mid-1960s, al-Banna was drawn into the politics of the Palestinian resistance movement where he fell in with Yasser Arafat's Fatah organization. Here he apparently adopted his nom de guerre (Abu Nidal, Father of the Struggle) and developed, during King Hussein's bloody suppression of the Palestinian fedayeen in September 1970, a deep hatred for the Hashemites. It was during these years as well that he also began to develop links with other radical Palestinian groups committed to the use of international terror. He may also have maintained ties with Fatah's own terrorist arm, Black September. By 1971 he had been appointed PLO representative in Baghdad. It is here that he became intrigued with the radical approach of the Iraqi Ba'th and more disillusioned with what he perceived to be establishment PLO policies.

By 1973 the stage was set for a formal break with Arafat and Fatah. Several events seemed to converge to push him away from Fatah. At a time when Fatah was beginning to limit its involvement in international terrorism, Abu Nidal was just getting started -- carrying out attacks against the Saudi embassy in Paris and an attempted hijacking at Rome airport. He had been greatly influenced by the earlier activities of Black September, and became convinced that transnational terrorism had to play a central role in Palestinian strategy.

At about the same time, the October 1973 war and the possibilities of movement on the diplomatic front had prompted Arafat to begin cultivating a more respectable international image and to adopt a more flexible political program. Abu Nidal vehemently opposed any tempering of the PLO's commitment to the armed struggle and felt excluded from the diplomatic and political world in which the PLO began to operate. He was not alone in his opposition. This tactical shift in Fatah's policies created a real dilemma for those in the movement committed to the PLO's maximalist goals. In 1974, George Habbash's PFLP temporarily left the PLO's executive committee to protest what it saw as Arafat's accommodationist policies.

Unlike Habbash, however, Abu Nidal did not return. That year the break with Arafat became final amidst accusations that Abu Nidal was implicated in a plot to eliminate Fatah's top leadership, although Abu Nidal claims that the rift was triggered by Fatah's campaign to kill its own people. Abu Nidal was tried and sentenced to death in absentia. The break with Arafat was now complete and a vendetta sworn against Fatah that would become a key component of Abu Nidal's raison d'etre.

For the next nine years, Abu Nidal would operate out of three Middle Eastern capitals -- Baghdad, Damascus, and Tripoli, not coincidentally regimes that were in the forefront of opposition to any Arab-Israeli accommodation. For the Iraqis, with whom he cooperated closely until they broke with him and expelled him in the early 1980s, he offered a useful tool in their campaign against their arch-rival Syria. In fact, after the Syrian move into Lebanon in June 1976, Abu Nidal adopted the name Black June as a cover for his anti-Syrian activities -- undertaking attacks against a range of Syrian and Palestinian targets.

For the Syrians, with whom he still maintains ties, Abu Nidal became an asset in Assad's efforts to pressure Jordan and the PLO. As Arafat's dialogue with Jordan's King Hussein intensified, so did Abu Nidal's anti-PLO and Jordanian activities. In 1983, Abu Nidal's organization was thought to have been involved in the assassination Issam Sartawi, the PLO's leading advocate of accommodation with Israel; he is also thought to have been involved in the murder of Fahd Qawasmeh, a moderate West Bank mayor deported by the Israelis. This attack, occurring in broad daylight in a residential area of Amman, was doubtless intended as a not-so-subtle message to King Hussein that there would be a price to pay for ignoring Damascus's interests on Arab-Israeli issues. Throughout 1985, Abu Nidal continued to attack Jordanian diplomats and airline facilities.

Finally, for Libya, with whom he has been strengthening ties since mid-1984, Abu Nidal became another hit man for Qaddafi's terror squads. His choice of an Egyptian airliner in the recent Malta hijacking and recent operations in Europe coincide with Libya's support for international terrorism. Indeed a look at Abu Nidal's recent operations -- culminating in the December 1985 attacks in Rome and Vienna suggest that he has -- while not severing his Syrian connection -- brought his tactics into closer alignment with Libyan interests. In a September 1985 interview in Kuwait he claimed to fully support Egypt's Revolutionaries, a group that has claimed responsibility for killing Israeli diplomats in Cairo. Such operations concide with Libya's goal of embarrassing Mubarak and creating tension between Israeli and Egypt.

But what of Abu Nidal's goals and objectives? What does he hope to achieve and what do his patrons hope to gain?

In following Abu Nidal's trail over the past decade, one fact is unmistakable. The violence and terror he sows is not directed at any achievable political goal. While Abu Nidal pursues tactical ends -- publicity, intimidation -- he does not seek to use terror to achieve Palestinian rights or a state in his lifetime or even in that of his children. For him the struggle against Zionism and all of its supporters is timeless and continues without regard for accommodation, compromise, or negotiation. "The fact that the Zionists have taken my Arab homeland is for me more than a crime," Abu Nidal asserted last fall. "For me it would be a crime if we permitted the Zionists to leave our homeland alive." It is here, in a world of grievances that can never be addressed, of injustices that can never be righted and of unending vengeance that Abu Nidal operates -- impervious and opposed to all forms of accommodation or moderation.

Within this view of revolution and terrorism, however, Abu Nidal has pursued two basic objectives. First, he has sought to challenge Fatah, and Arafat in particular, by maintaining that he is the legitimate heir to Fatah's original policies. Much of the idelogical rationalization for his policies rests on his accusations that Arafat is deviating from the principles of the total destruction of the "Zionist entity" and the pursuit of true Arab unity.

It would be misleading, however, to suggest that Abu Nidal's only enemy is Arafat and the Israelis. Coincident with his total opposition to the Arab establishment is his virulent hostility to "bourgeois and pro-imperialist" Arab regimes whom he views as corrupt and venal. Although Jordan is a particular object of his hatred, Hussein is not alone. "My enemies are the slovenly and chaotic states of our Arab society, as well as the suppression and seduction of our young generation," Abu Nidal recently declared. Like other Arab revolutionaries of the 1950s and 1960s, Abu Nidal places a high premium on the importance of overthrowing these regimes as a prerequisite to Arab unity and thus the liberation of Palestine.

Abu Nidal, however, does not exist in a vacuum and it is crucial to understand the intra-Arab and international environment in which he operates. In a sense it is this Arab and international support that elevates him from the garden-variety terrorist to the transnational terrorist league in which he plays. The Arab states that have backed Abu Nidal -- Iraq at one time, Syria and now Libya -- and the East Europe bloc nations did not create him; he is not simply a kind of Palestinian or "have Kalashnikov, will travel." Nonetheless, the support these states provide is vital to the effectiveness of his operations. While there is clearly a transnational terrorist network from which a man like Abu Nidal could benefit, his ability to operate and survive for over a decade and a half is directly linked to the assistance he derives from external sources.

The Libyan connection is only the latest of Abu Nidal's tactical alliances, and it's no coincidence that the states that have most actively supported Abu Nidal over the past 10 years are those that have historically been most opposed to reconciliation with Israel. They have also at one time or another been involved in major confrontations with those moderate states -- Egypt and Jordan -- that have been pushing for peace with Israel. It is also these states that have been most adept at using terror not only in the Arab arena but abroad as well in the service of their own goals. Although Abu Nidal's Arab support is thus relatively tightly circumscribed, there was always a market for his services. When Arab states' interests and behavior shift, as in the case of Iraq in the early 1980s or in the case of Syria, 1984-1985, Abu Nidal moves on to another patron. Thus, it is possible for Abu Nidal operatives to train in the Bekaa Valley and yet be given false passports, money, and weapons by Libya.

The lessons drawn from studying Abu Nidal and his world are not heartening ones. Indeed the consistency and effectiveness of his operations lead to the conclusion that his brand of terrorism is likely to remain a permanent feature of the Middle East's political landscape. Even more sobering is the recognition that Abu Nidal's terror has become very much a permanent fixture of shifting rivalries between Arab regimes. He remains effective because he is willing and able to provide services for a variety of patrons.

Nonetheless, in the end there are limits to what Abu Nidal can hope to achieve. He represents no constituency with any real power; he can never achieve anything positive for Palestinians. He can only destroy and intimidate until he himself is destroyed. More like him may follow, but their legacy will not be any more enduring.