There is no doubt about at least one of Carlos's actions. A French court sentenced him to life imprisonment for the murder of two counter-espionage agents in Paris in 1975. Later that year he staged an audacious attack on the headquarters of Opec in Vienna. Eleven oil ministers were kidnapped and taken on an odyssey to Tripoli and Algiers, in those days the Mecca and Medina of Arab radicalism. The Saudi oil minister, Ahmed Zaki Yamani, later recalled a smooth, calm and multilingual Carlos who combined ruthlessness with intellect.
After that episode the myths proliferated. One year Carlos was supposed to be acting at the whimsical behest of Colonel Gaddafi. The next he was doing the dirty work of Iraqi intelligence. Then he was said to be residing in the discreet security of Damascus. Assiduously fed by propagandists, excitable journalists traced his hand in every insoluble deed of violence. Finally, an Israeli newspaper declared him dead and buried in the Libyan desert.
When all this nonsense is stripped away, Mr Pasqua and the French authorities should make public what testimony can be gleaned from their captive. The information is relevant to political judgements which governments must make today - and also of importance to modern historians.
One unresolved issue is whether in practice there exists a statute of limitations on political crime. Carlos belonged to the Marxist, radical and secular strands of Arab revolutionary politics. His closest known links were to the Popular Front for the Liberation of Palestine, a group whose engaging, and now elderly, founder still lives in Damascus. Many of the actions attributed to his hand depended on the support of a state apparatus. If Carlos is to testify about who really paid and instructed him, there could be unhappy implications for the governments of Syria, Libya and Iraq, all of them run by the same coteries as two decades ago.
There must be many people who do not wish this eminent prisoner to talk. But the sensitivities of modern diplomacy should not be allowed to overcome the demands of justice. Should that embarrass, for example, President Assad of Syria, too bad. It would be unlikely to derail a peace process that may yet end the conflict that fostered Carlos and his kind.
There is a particular piquancy to the fact that Carlos should have been captured by the Islamic dictatorship of Sudan and handed over to a French interior minister who has recently declared all-out war against fundamentalist violence. Mr Pasqua is, of course, no stranger to the murkier byways of Middle Eastern intrigue. It was he who employed the talents of a Corsican secret agent to retrieve French hostages from Beirut in 1988. Whatever understanding may have been reached between Paris and Khartoum may never be vouchsafed to us.
The pertinent point to note is that changing times make for strange alliances. The world has moved on from the era when a young Carlos (was he born in 1949 or 1950?) entered the ranks of the Latin American left and merged into the worldwide stream of revolutionary consciousness that identified, as he did, the twin evils of 'Zionism and imperialism'. Gone are the days when graduates of Patrice Lumumba University in Moscow were deployed in the service of their antitheses, 'peace and socialism', usually to generate neither. Yasser Arafat has made peace with Israel and secular Arabs now turn their worried eyes upon Algiers, not Washington. Carlos may be history, but his is a history that cannot be shirked.Reuse content