FUTURE HISTORIANS almost certainly will label the 1970s the decade of the terrorist. There were wars: guerrilla wars, civil wars, full-scale military contests. There were mad bombers, mass murderers and mass suicides. The political terrorist, however, dominated the headlines of the era.

Being inherently dramatic, terrorists attract not only headlines but the interest of journalists. Claire Sterling is an American foreign correspondent who has been based in Italy for 30 years. From Rome, Sterling has provided an account of international terrorism's first decade -- "Fright Decade I" she calls it.

The Terror Network is a well-written book. At times its tone is a bit lurid, but no more so than most books written about terrorism -- which itself is lurid. Terrorism is the political pornography of our times.

"Nothing is history could equal the bands of professional practitioners dispensing violent death in forth-odd countries on four continents today," she writes at the outset of her book. "Methodically trained, massively armed, immensely rich, and assured of powerful patronage, they move with remarkable confidence across national frontiers from floodlit state to stage, able at a word to command the planet's riveted attention."

The portrait she paints of the terrorists as individuals doesn't quite match the prose. Behind the gun barrels and stocking masks through which most terrorists present themselves to the world, they emerge as emotionally crippled, violence-prone, publicity-loving, often incompetent social defects -- casualties of childhood horrors, candidates all for a psychiatrist's notebook.

Their planning is frequently haphazard. They blow themselves up with faulty timers. They hide their weapons in public toilets, then can't retrieve them. They aim their bazooka at a parked El Al airliner and hit a Yugoslav aircraft instead.

They suffer the tensions of living underground. They squabble over who is sleeping with whom. They are constantly on the run. They quit. They die in shootouts. They talk in prison. They commit suicide. One looks hard for a hero among them.

Sterling has a taste for gossip. We learn that Giangiacomo Feltrinelli, the eccentric millionaire publisher who, like some modern Prince Kropotkin, chased about the world seeking the company of revolutionaries shoveling out money to the far left fringe groups, dressing himself up in the Uruguayan Tupamaros' style of military dress as if revolution were some kind of costume party, was born with a shriveled penis. He accompanied his lovemaking with recordings of gunfire and martial music.

Petra Krause, who ran a "weapons takeout service" for terrorist groups, spent the first three years of her life in the concentration camp at Auschwitz where both her parents died. She was "exchanged along with a batch of two thousand babies for a shipment of Swedish steel."

Norbert Krocher, the mastermind of a half-baked plot to kidnap a Swedish cabinet minister, kept a diary of his terrorist plans, his "secret basement meetings, comrades marked for isolation or liquidation, the girls he slept with and prescriptions he renewed for recurrent bouts of gonnorrhea." He dedicated his manuscript to "Members of the World Movement Against the Zombies." The members were anybody against the established order. The Zombies were everybody else.

Somehow the group portrait contradicts the words Sterling used in her book to describe "the terror network." Do these same people staff the "terror bank" of expert personnel?

The Terror Network will be widely read. It is being published simultaneously in France, Germany, Great Britain, Italy, the Netherlands, Australia, Mexico and Spain. (It is on sale at the bookstore in the headquarters of the Italian Communist Party in Rome.) Reader's Digest will carry a condensed version of the book for its 18 million readers.

The Terror Network will be an influential book. Its timing is perfect. Its publication coincides with the inauguration of a new administration in Washington that in its public rhetoric has elevated the problem of international terrorism to an issue of paramount importance. Moreover, the author's theme that the Soviet Union is behind much of today's terrorism coincides with and could reinforce the attitudes of administration officials who are inclined to blame Moscow for most of the unrest in the world.

A friend of mine recently observed that at the moment there are three kinds of people in Washington: Those who have always believed the Soviet Union is responsible for terrorism; those who want to believe that it is; and those who, in order to maintain their influence in government, must pretend to believe. Because the book could have major implications for U.S. policy, its arguments merit a careful examination.

Sterling offers two major themes. The first is that the disparate terrorist groups of the world, or at least most of them, are somehow linked with one another, which is true. Japanese terrorists train in Middle East terrorist camps and carry out operations with Palestinian terrorists. Italian terrorists pick up weapons from Palestinian terrorists and in return help run guns to the Palestinians. Basque terrorists offer the IRA revolvers in return for training in the uses of explosives. These stories are by now well known.

The second theme of the book is that somehow all of these terrorist groups ae linked directly or indirectly to the Soviet Union. More than that: Sterling suggests that the Soviet Union and its East European, Cuban and Palestinian proxies are behind "the terror network." She implies forethought on the part of the Soviet Union and its satellites.

She never actually states if as a fact. She implies. She insinuates. Like a magician, she conjures up the impression that there is a Moscow master plan, leaving the audience to flesh out the illusion.

The book's subtitle, "The Secret War of International Terrorism," suggests that, as in a war, there are two sides, a central command, and the marshalling of armies. The book's dust jacket tantalizes: President Carter's adviser on terrorism in the National Security Council asks her, "You don't really believe this bunk about international terrorism do you?" She answers, "Yes, I do." But what bunk is he asking about that she believes? Near the end of the book she writes, "In effect, the Soviet Union had simply laid a loaded gun on the table, leaving others to get on with it." A picturesque phrase, but what exactly does it mean? If it means that the Soviet Union provides weapons and training to guerrilla groups fighting various kinds of Western-oriented governments in the Third World with terrorist tactics, this is so. If it means that Soviet allies and satellites provide support to an even wider range of violent groups, this also is amply documented. Cuba, North Korea, Libya and South Yeman provide training facilities and other forms of support to Latin American, Middle Eastern and West European terrorist groups.

If it means that the Palestinians, who have received Soviet training along with Arab financing, have in turn provided training, weapons, asylum or other forms of assistance to terrorist groups in Western Europe -- Italy's Red Brigades, Spain's Basque terrorists -- again, this is well known and long known at least among those who study the problem. These relationships have been the subject of earlier books, though less ballyhooed than this one. They have been widely discussed in the press, as Sterling's footnotes attest.

However, if the "Sterling thesis" is meant to go further than that and imply -- as many are taking it to imply -- a Soviet blueprint, Soviet instigation, Soviet direction, or Soviet control, then the book offers no new evidence, and that which is offered does not make its case. In fact, the author's own statements are ambiguous.

Speaking of Henri Curiel, leader of a Paris-based apparatus that funneled money and arms to leftist groups around the world, she writes: "Every major counterespionage agency in the West had a file on him, and almost anybody in the trade reading through these would assume he worked for the KGB." Would they assume correctly? She never clears up the mystery; she writes later, "The questions still nag at Western security agents, who to this day haven't been able to pin a piece of totally incriminating evidence on Curiel. 'The Agency kept telling me the fellow was KGB; but I don't see it,' one senior CIA operative in Europe remarked to me . . . 'He was KGB all right," said another."

That a number of left-wing Italian terrorists traveled to Czechoslovakia is well known, but no evidence is offered that the Russians or the Czechs were controlling or directing the activities of the Red Brigades. I asked a senior intelligence official what he considered proof of direct Soviet involvement in the activities of the Red Brigades. "One dollar from a Soviet source to Italian terrorists," he answered. Indeed, the Italian terrorists had serious financial problems, as Sterling herself points out. Raising the $10 million a year required for safe houses, payrolls, travel expenses "was a continuing drain on the organization's human resources." It seems a paltry sum for a group supposed to have powerful foreign backers.

The distinctions between the words exploitation and instigation, linkage and central direction, support and control, may be subtle but they are crucial. Policies derive from models of interpretation. How we combat terrorism depends on how we perceive the problem. Some may consider it naive to demand hard evidence, something closer to a smoking gun than newspaper clipping or the assumptions of one senior intelligence official versus the skepticism of another.

But to insinuate that terrorism always was or is by now fully controlled by Moscow may be to underestimate its depth, its extent, and its danger. It could even deflect us from the central problems of terrorism. It that should happen, The Terror Network truly would be, in the classic sense of the phrase, a red herring.