Attackers Move More Softly

THERE have been few spectacular terrorist incidents since the bombing of Pan Am Flight 103 almost a year ago. But terrorism has not exactly faded away. Despite progress in finding and bringing terrorists to justice, some analysts are worried that United States policy is too passive. Middle East terrorism may only be in a lull, and Latin American drug dealers are rapidly adopting terrorist methods, they warn.

``We need to undertake the slow, patient infiltration of these gangs,'' says Uri Raanan, director of Boston University's Institute for the Study of Conflict, Ideology, and Policy.

Dr. Raanan is one of several experts who contend that US policy, in particular, is still relying too heavily on a ``passive defense'' that allows terrorists to choose when and where to strike. Raanan and others advocate ``active measures'' like infiltration to give early warning of terrorist operations.

Events last week brought terrorism back onto the world stage, illustrating both progress to thwart it, and its ongoing operations:

Police in Sweden raided the apartment of a Palestinian accused of terrorism and reportedly found evidence linking him with the bombing of Flight 103.

In West Germany, the Red Army Faction murdered the country's leading banker.

Palestinian terrorist leader Abu Nidal was rumored to be under ``house arrest'' in Libya, while his organization has reportedly been racked by internal strife.

Several members of the Lebanese Shiite Hizbullah were arrested in Spain trying to smuggle explosives. Meanwhile, French officials announced they had uncovered a Hizbullah network operating in West Africa.

Step by step, investigators have pieced together the puzzle of the Pan Am bombing. As they have done so, sporadic press reports have linked Ahmed Jabril, leader of the Syrian-based Popular Front for the Liberation of Palestine-General Command (PFLP-GC) with the airliner bombing. The reports say Mr. Jabril acted at Iran's request. Iran and Jabril deny the allegations.

ABC News and other press reports have linked Jabril with Muhammad Abu Talb, a member of the Palestine Popular Struggle Front. Mr. Abu Talb is alleged to have smuggled the bomb to Malta, where it was reportedly put aboard an Air Malta flight to Frankfurt. There it was reported transferred to Flight 103.

Clothing from the suitcase in which the bomb was hidden has reportedly been traced to a store on Malta that Abu Talb visited in October 1988. Yesterday, a Swedish court ruled that the clothing could be used in the Scottish investigation of the Flight 103 bombing.

Abu Talb has been awaiting a verdict on separate charges of murder and attempted murder in connection with bombings in Copenhagen, Amsterdam and Stockholm in 1985 and 1986. Scottish investigators were reportedly considering asking Sweden to extradite Abu Talb. Abu Talb denies any involvement in the bombing of Flight 103.

Operations on several fronts

The murder of West German banker Alfred Herrhausen, apparently by the Red Army Faction, brought to an end a year-long lull in that group's activities. German police say they are seeking two men who put a powerful bomb on a bicycle in Bad Hamburg and detonated it as Mr. Herrhausen's car passed by.

It was the first RAF attack since an unsuccessful attempt in September 1988. A US official, who asked not to be named, says it appears the RAF ``wanted to show they are still there, and strike out against the capitalist class at a time when there is talk about German reunification as the communist system crumbles.''

In Spain, at least three of the men arrested by police were members of the Lebanese pro-Iranian Hizbullah, or ``Party of God.'' They allegedly were planning attacks on US targets in Europe. Hizbullah is an umbrella organization that includes several extremist groups, many of which hold US and other Western hostages in Lebanon.

The Hizbullah network the French uncovered operating in West and Central Africa has apparently been operating since 1986. French and US officials told the Los Angeles Times that a Hizbullah cell in Africa is believed responsible for the bombing of a French airliner in September, in which 171 people died. Abu Nidal's purported problems

Conflicting reports last week said notorious Palestinian terrorist Abu Nidal was either under house arrest in Libya, recovering from a heart attack, or dying of a terminal illness.

The reports come amid evidence of a fighting in the ranks of Abu Nidal's Fatah Revolutionary Council that has reportedly killed 200 or more members. The US official says the fighting is apparently a bid to topple Abu Nidal from the group's leadership.

Abu Nidal is one of the world's most wanted terrorists. His band is held responsible for more than 900 deaths in roughly 100 separate attacks. Some reports claim that Libyan leader Col. Muammar Qaddafi had Abu Nidal detained in order to enhance his own standing in the West. `Passive' resistance not enough

Some experts say terrorism is spreading from the Middle East to Latin America, as Colombian and other drug traffickers retaliate against governments that target their wildly profitable operations. These analysts point to the crash last week of a Colombian airliner. While the cause is not yet known, telephone callers have claimed a narcotics cartel blew the plane up to kill police informants on board.

This kind of ``low-intensity conflict is the biggest strategic problem we face,'' says Robert Kupperman of the Center for Strategic and International Studies in Washington.

There is no real consensus in the US on how to deal with terrorists. With a few exceptions, the Reagan and Bush administrations have concentrated trying to bring terrorists to justice in US courts.

But pursuing terrorists through the criminal justice system is not enough, Dr. Kupperman says. When terrorists strike, the US should take immediate diplomatic and economic action against the perpetrators and their hosts, he says. ``When that fails, we should hit them militarily.''

Boston University's Raanan and others advocate ``active measures'' like infiltration to give early warning of terrorist operations. Infiltrating these groups also ``helps to create fratricidal strife within these organizations, he says. Some progress

But the US official says there has been progress against terrorism. He says terrorists have turned to bombing aircraft because it was getting too hard to hijack them. The challenge, the official says, is to tighten security to keep bombs off planes. The Israeli airline El Al has succeeded at this, he notes.

``The [security] people are now in place. But they must be well trained,'' he says. The next step, he says, must be to expand the security net to the feeder airports which connect to flights in major air hubs.

There is also more cooperation between nations in tracking down terrorists, the US official says. ``A lot of countries are no longer willing to let [suspected terrorists] go. There have been more trials, and more terrorists are in jail.''