It seems strange that so little is known even now about the American hostages' Iranian "student" jailers. In nearly 15 months, we never did find out just who they were and whose orders they were taking, when and where they were trained, by whom and to what end, whether for an Islamic or Marxist revolution or both. If nothing else, though, we can at least put them in their proper international context.

They were accomplished terrorists: the kind who were made, not born, whose profesional counterparts may be found in dozens of countries today from Japan and Turkey to Italy, Spain, West Germany, Northern Ireland, much or most of Central and South America. Whether they learned their craft abroad or at home has not been established but hardly matters. For Iranians especially, the most high-powered instructors in the world would have been available either way.

Iran was singled out for special attention long ago by a global terrorist network. Thousands of Iranians learned the arts of urban guerilla warfare that way in the '70s, under the expert tutelage of Cubans, East Germans and veteran Palestinian warriors. The whole of Iran's revolutionary underground -- including both Islamic and Marxist wings -- has been locked into the network for more than a decade.

The Iranians have been a privileged elite in this network since it first took shape, under radical Palestinian auspices. They were among the earliest foreign recruits in Middle East guerrilla camps: all such camps, in Syria, Lebanon, South Yemen, Libya, Algeria, but especially those run by George Habash's Marxist Popular Front for the Liberation of Palestine.

Soon after Ayatollah Khomeini swept into power in January 1979, the PFLP's chief spokesman, Bassam Abu Sharif, spoke proudly of his group's having "been in touch with the Iranian people's struggle for the past seven years," providing them with training "in everything from propaganda to the use of weapons." On the very day he spoke, the Journal de Geneve reported the recent arrival, in Iran and elsewhere around the Persian Gulf, of yet another terrorist band freshly graduated from a PFLP camp in Beaufort Castle near Tyre, Lebanon. the band had just spent eight months in the camp, trained by Cuban instructors there, "in street and desert fighting, attacking people and buildings, regular demolition operations and sabotaging oil installations," the Swiss paper reported.

It was certainly neither the first nor last such band carefully groomed to fight inside Iran. As far back as Dec. 19, 1971, the Lebanese paper al-Ahad reported that "the Palestinian revolution has opened the way for many Iranian fighters to benefit from practical training in the use of arms. . . . This first aid began in 1968 when a contingent of the Iranian revolutionary movement left Iran for training with the resistance movement," the paper went on. "After their return to Iran they began to train other members. . . . Owing to the direct influence of the armed Palestinian struggle, revolutionary groups began to study armed struggle and to carry out armed actions inside Iran."

How many of them were at it -- by 1971, eight years before Iran's Islamic revolution peaked -- is suggested by the arrests of 75 Iranians in a single group returning to their country that year, all trained and armed by the PFLP.

Guerilla training was only part of their accumulating worldly experience. Iranian terrorists have been honored guests at every international terrorist summit meeting known to Western intelligence services, starting with the one sponsored by Habash in May 1972 in Badawi, Lebanon. They belonged to the inner circle around the celebrated Carlos the Jackal, directing continent-wide multinatinal terrorist operations for Habash out of Paris. From their own Paris headquarters, they worked closely with the Turkish People's Liberation Army (whose office they shared until the French police raided it), the IRA Provisionals, the Spanish Basque terrorists in ETA, the Japanese Red Army European team, the Swiss anarchists running a weapons takeout service for terrorist bands of all Western Europe, the German Baader Meinhof Gang, helping them to plot the shah's assassination in 1975, among other things.

None of this proves that our particular Iranian "students" emanated directly from the international terror network. If not, though, a lot must have rubbed off on them from others who did. They had the benefits, besides, of its prodigious intelligence-gathering machinery, logistic support, expert counsel on the media, worldwide propaganda services, money and couriers from the network's Libyan branch and highly specialized Palestinian personnel to mine the U.S. Embassy compound. Whether as members or clients of the network, they obviously got much further with it than they ever could have done without it.

Some Americans may find all this academic, now that the hostages are free. In fact, it is central to the future security of the United States and its Western allies. The seizure of the American hostages in Tehran was hardly unique. Something very much like it has been happening to our friends abroad all along. Practically every one of them suffered a similar trauma at the terror network's hands during the '70s -- Fright Decade I. If we cannot prevent it, we might at least brace ourselves for a fresh round of shock, bound to follow as night follows day in Fright Decade II.