New US data show terrorism ebbed in 1986. 40% drop in Europe credited to joint effort by Western nations

More hostages are captured in the Middle East. European governments grapple over how to handle suspected terrorists now in custody. Americans hastily leave Beirut. Terrorism continues to bedevil nations and individuals. But according to experts in the United States, the current turmoil could obscure a more important, underlying reality: The West has made substantial progress in reducing terrorism worldwide.

New figures to be released soon by the US State Department show a significant decrease in many kinds of terrorism during 1986.

In Europe, incidents of international terrorism are down 40 percent from 1985. Worldwide, the total number of terrorist incidents is also down, and so is the number of fatalities as a result of terrorist attacks.

But the picture is not uniformly bright. Overall, the number of people injured in terrorist incidents in 1986 is up. And terror incidents against Americans and American-owned properties continued to increase, as did the overall number of terrorist incidents in Latin America. Nevertheless, the overall number of terrorist incidents for 1986 - approximately 750 worldwide - is off from the 1985 total of 782.

``I'm not going to pretend that we've beaten the problem,'' says a senior US official. ``But in the past few years, we've had quite remarkable progress.''

US officials note that the number of terrorist incidents linked directly to Libya was also down during the last half of 1986.

``It's clear,'' a senior administration official said recently, ``that there has been [a] decrease in Libyan terrorism, if you start to measure the incidents. They are down now, they're isolated....''

``You can't measure what didn't happen,'' says another US official, ``but we believe that some lives have been saved.''

These assessments, based on preliminary US government figures, could be adjusted later. And experts caution that much of the apparent progress could be undermined by events - such as a decisive turn in the Iran-Iraq war, or a flare-up of tension in Israeli-occupied areas in the Middle East. Some officials, uncertain about the impact of revelations of secret Reagan administration efforts to swap arms for hostages, say they could possibly lead to more hostage-taking.

Some Western countries have privately registered strong disapproval of the clandestine American arms trading with Iran to secure the release of American hostages. But, according to US diplomats, not a single American ally has indicated that, as a result, their own efforts to combat terrorism and hostage-taking will be relaxed. It is that cooperation that seems to have turned the tide against terrorism in 1986.

Members of the European Community and the leaders of seven Western nations, meeting at a Tokyo summit in May 1986, agreed to step up cooperative efforts against terrorism. These include arms embargoes, improved extradition procedures, and limits on the size of diplomatic missions of countries suspected of backing terrorism. In addition, EC countries agreed that no member would accept any persons expelled from another member state on grounds of suspected involvement in terrorist activities.

The strategy seems to have produced some results, particularly in Western Europe, where there were 218 reported terrorist incidents 1n 1985, according to the US State Department. The comparable figure for 1986 is expected to be 130. And the number of terrorist incidents in Western Europe related to the Middle East - what experts call ``spillover'' terrorism - was also down substantially, from 74 incidents in 1985 to just over a third that total, or 25 incidents, for 1986.

The cooperation can be measured in dollar terms: Last year Congress appropriated and authorized a record amount of money - nearly $10 million - for international efforts against terrorism. The US has paid the bills for some 3,000 people to undergo training or take part in expert conferences on counter-terrorism.

As recent events in the Middle East have demonstrated, however, there continue to be large gaps in the Western antiterrorism effort. One major problem, according to informed sources, is the lack on intelligence data. One expert, who asked not to be named, says that US intelligence from the Middle East is surprisingly ``wispy.''

Not much is known, for example, about the secretive networks of Middle Eastern terrorists who claim responsibility for the latest round of kidnappings in Beirut. The official concedes that ``we've never heard of'' one of the groups that claims to be holding Americans, the ``Islamic Jihad for the Liberation of Palestine.''

The other group now holding Americans, ``Oppressed on Earth,'' is believed to have ties to the radical Hizbullah (Party of God), which in turn has links with the government of Iran.

Iran continues to figure in many of the current incidents of terrorism and hostage-taking, according to US officials. The Iranian government denies that charge but does acknowledge that some groups who have taken hostages do have ``respect'' for Iran's brand of Islamic fundamentalism and could be influenced by it. The price for using that influence? The provision of arms in the war against Iraq.

That, according to US officials, is the kind of argument that some in the Reagan White House may once have found persuasive, but no more.

``Any country which has influence on hostage-takers,'' one US official says, ``has the clear responsibility to get the hostages released.'' He continues, ``It's clear the Iranian government has links with Hizbullah ... falling somewhere between influence and control.''