The Jackal: Freedom fighters or terrorists? The shadowy figures who dealt in death and destruction

Carlos the Jackal is not alone with his fame. There are others whose dedication to violence has gained them an almost equally high profile worldwide. Some are now dead, others are still on the run, others live quietly respectable lives.

Of all terrorists dead or alive, Abu Nidal is the most feared. He has become synonymous with the concept of a shadowy terrorist mastermind. All photographs are long out of date, and few facts about him are entirely undisputed. He has been implicated in dozens of terrorist attacks in the past 20 years, including attacks on Rome and Vienna airports in which 17 people died and an attack on a Greek ferry in which 11 people died.

He was born in Jaffa in 1937, and was ambassador for Yasser Arafat's PLO in Sudan and Iraq. But in 1973 he quarrelled with the PLO, saying it was too moderate. He has threatened to kill Mr Arafat, and was responsible for killing two of Mr Arafat's senior aides in 1990. He is reportedly based in Libya, though it is unclear whether he has freedom of movement there. According to some reports, he has been ill with cancer.

Almost equally well known in her day was Leila Khaled, who twice hijacked planes on behalf of the Palestinian cause. She now lives in Jordan, a 53-year-old mother with teenage sons. But she remains true to her convictions, insisting that she was a freedom fighter not a terrorist, and that the hijacks were the only way to draw attention to the Palestinian cause. A hijack attempt on an El Al aircraft in 1970 ended with her colleague shot dead, and with Khaled arrested in the UK. But she was released after just a few weeks, in an exchange of seven captured Palestinians for 300 civilian hostages.

The most famous European terrorists in recent decades have been Andreas Baader and Ulrike Meinhof, who jointly gave their names to the group that was at war with the West German state in the 1970s. For some, the Baader- Meinhof group were mindless terrorists; others argued that the group forced West Germany to confront its history. Baader and Meinhof died in prison in 1976 and 1977 respectively - suicides or convenient deaths, according to one's point of view. A number of lesser-known members of the Red Army Faction (an offshoot of Baader-Meinhof), are still on the run; they appear on "Wanted" posters all across Germany.

The word "terrorist" means different things to different people. All over the world, different groups advocate violence in order to get rid of what they perceive as illegitimate regimes at home. Increasingly, Western powers are taking a tough line against those who advocate violence in their home countries, however undemocratic those countries may be. Egypt complains that Islamic radicals are at liberty in the UK. British legislation looks set to be tightened up, in the months to come. - Steve Crawshaw