Terrorism is back on the international agenda, and its practitioners have become bolder and more imaginative than ever.

In West Beirut, Abu Nidal's spokesman called a press conference -- of all things -- to announce the seizure of eight Israelis, including two children, from a boat off the Gaza Strip. The spokesman threatened that all would be killed if there was retaliation by the government of Israel.

Meanwhile, in New York, a Syrian ambassador proposed that the United Nations convene an international conference to (re)define terrorism to exclude just such activities as Abu Nidal's. ''This conference, through its lofty, noble objectives, is indispensable for the elimination of the deliberate confusion between terrorism and the struggle of peoples for liberation,'' said Ambassador Ahmad Fathi al-Masri.

In the Syrian view, what is commonly and mistakenly called terrorism -- kidnapping civilians, bombing discotheques and supermarkets, hijacking airliners -- is not terrorism at all. It is the ''inevitable outcome'' of ''colonialism,'' of ''racism'' by ''settler-colonialists'' and ''racist regimes.''

The world is confused, says Syria's representative. Violence used by Abu Nidal, his colleagues and protectors is not terrorism. It is a liberation struggle. Terrorism is the force used by Israel or West Germany or France or the United States to protect itself. In Syria's view, the confusion about what is and is not terrorism is itself part of a conspiracy foisted on the world by ''a small group of powerful, influential states'' which ''seeks to halt the people's struggle for liberation from the shackles of colonialist hegemony.'' (They really talk that way in the United Nations.)

The Syrian ambassador does not doubt that a U.N. conference would see things his way. I do not doubt it either. The General Assembly has long since passed resolutions that legitimize ''armed struggle'' and struggle by ''all necessary means'' for ''national liberation movements'' and has declared it a ''criminal act'' to resist. By the mid-1970s, moreover, the list of permissible targets of ''national liberation movements'' was extended from ''colonial'' to ''racist'' regimes. And on Nov. 10, 1975, the 37th anniversary of Kristallnacht, the General Assembly formally declared Zionism a form of racism and Israel a legitimate target of a ''national liberation movement'' (the PLO). Henceforth Israel had no ''right'' to resist PLO attacks.

The General Assembly has repeatedly reaffirmed this upside-down ''doctrine of legitimacy,'' which permits everything by ''national liberation movements'' -- including violence against unarmed civilians -- and condemns self-defense by their victims.

Thus ''national liberation movements'' may attack school buses or supermarkets, burn alive unarmed civilians, and never be condemned for ''an act of aggression'' (which is forbidden by the U.N. Charter). Their violence is by definition ''self-defense'' permitted by the charter. Their victims are by definition ''aggressors,'' condemned by the charter and international law.

Terrorism has never been explicitly incorporated into this doctrine. It is this oversight that Syria seeks now to correct with its call for a U.N. conference on the definition of terrorism.

Why now? Doubtless because the government of Syria has been publicly embarrassed in the last two years as it was linked to the bombing of the Rome and Vienna airports and when a London court established direct ties between Syrian intelligence and the plan to bomb an Israeli airliner. It would appear that Syria intends to deal with the embarrassment of being caught red-handed through its new U.N. initiative.

As Israel's U.N. ambassador, Benjamin Netanyahu, said in a powerful speech on the Syrian proposal: ''They conceived the idea of this conference in order to change the terms of reference about terrorism. In the past they denied that they perpetrated these crimes. Now, having been exposed, they say they are not really crimes.''

Syria's chances of success were enhanced when its friend and ally, the Soviet Union, supported the idea of a conference, and a Libyan -- of all people -- was chosen to head the Sixth Committee of the General Assembly that is currently considering the proposal.

The United States opposed the proposal, but unfortunately its response, delivered by congressional delegate George William Crockett Jr., was too weak, confused and mealy-mouthed to be helpful. It pretended that ''exceptional unity'' existed in the ''international community'' regarding terrorism, but failed to note that the resolution embodying this unity has been invoked only once -- to condemn the U.S. bombing of Libya.

It is always tempting to excuse such U.N. proceedings as mere rhetoric. But definitions approved by the General Assembly eventually make their way into the ideas and values of the majority that endorses them.

The debasement of language is today, as when Orwell warned against it, a necessary accompaniment to the dehumanization of victims.