Should a pathetic old man of 94, badly maimed by a letter bomb he opened 20 years ago, and believed to be skulking somewhere in Syria, be brought to justice in Europe for crimes committed more than 60 years ago? In a world confusedly grappling with current dangers such as global terrorism, acute climate change and desperate disparities in wealth, health and nutrition, has the international community not far more pressing matters to prosecute?

The Austrian government appar-ently thinks not. Its justice minister, Maria Berger, has just announced that now is the "last opportunity" to capture and try prominent Austrian Nazis. In this context, her ministry has offered a 50,000 (£33,600) award for information leading to the apprehension of the 94-year-old Alois Brunner.

Even by the vile standards of prominent Nazis, Brunner was a particularly repellent figure. He was Adolf Eichmann's most enthusiastic lieutenant when it came to hunting, deporting and exterminating Jews. His most hideous crimes were committed in Greece.

The Italian leader Benito Mussolini, dreaming of easy military glory, ordered his troops into Greece at the end of 1940. The Greeks resisted heroically and the Italian soldiers were on the point of defeat when Hitler ordered a second, more effective, invasion. Still the Greeks fought on, now backed by limited numbers of British and New Zealand troops. But it was clear that they were no match for the Germans. The Greek commander, General Alexandros Papagos, movingly told the British: "You have done your best to save us. We are finished, but the war is not lost. Save what you can of your army, to win elsewhere."

The capitulation was bad news for the Greeks, and Greek Jews in particular. Brunner, who had joined the Austrian Legion in Germany in 1933, and the SS in 1938, set to work with relish. The biggest concentration of Jews (as many as 60,000) was in Greece's second city, Salonika (now known as Thessaloniki), where a successful Jewish community had been settled since the Spanish dispersion of 1492.

Brunner descended on Salonika's many Jews with what Adolf Eichmann's biographer Prof David Cesarani called "the utmost brutality". In the summer of 1943, 46,000 Jews were deported to the concentration camp Auschwitz-Birkenau, where they were exterminated. Some tried to claim Spanish protection, but as so often, Eichamann intervened to negate any case for exemption. One of the strongest Jewish settlements in the Balkans was simply eradicated.

Brunner's central involvement in this heinous crime is undisputed. But if he is to be hunted, captured and tried, you have to ask: to what end?

There must be a suspicion that the intervention of the Austrian government is symbolic, an act of retrospective tokenism. The present Social Democratic administration clearly wants to be seen as different from more right-wing Austrian governments of the past, who were often criticised for being soft on Austrian Nazis. Such criticism reached a crescendo when Kurt Waldheim, who had been a Wehrmacht officer in the Balkans, became Austria's president.

There is also a sense that the era of unceasing Nazi hunting ended with the death in 2005 of Simon Wiesenthal, an extraordinary man who dedicated his life to meticulous documentation of all the component crimes of the Holocaust. He tracked down many perpetrators enjoying new lives in South America and also southern Spain, where some reputedly remain. In so far as Wiesenthal has a successor, he is probably Efraim Zuroff, who five years ago co-founded an organisation called Operation Last Chance, tasked with working for the prosecution of all remaining Nazi war criminals.

Then there is the debate about how some Nazis were guiltier than others, which overlaps the notorious "only obeying orders" defence. Perhaps the most alarming aspect of the Holocaust, the worst mass crime of all time, is that so many of those who took part in deportations and executions were ordinary, common or garden citizens. They were certainly not ideologues or fanatics or crazed sadistic zealots. Yet how many instances are there of refusals to shoot innocent civilians being punished by death? None, according to the historian Mark Mazower. The Jews were relentlessly expunged, with bureaucratic and smooth efficiency.

That said, Brunner was worse than most. But what then of the most noble human quality, compassion? Given that Brunner is so old, and maimed, should he not be left to die in something akin to peace, if he can find it? Should compassion, forgiveness and mercy not be unlimited?

Possibly, but I and no doubt many others would baulk at that. Justice and retribution have their place too. Last century was the worst in human history and right at its evil heart was the Holocaust. Those of its perpetrators who remain at large must surely be punished in the name of all humanity, whatever their age and their personal condition.