But for many in the ancient cities of south-east Turkey and the immigrant shanty towns of Istanbul - and the Kurdish diaspora across the world - it will be a disaster. For the disaffected among Turkey's Kurdish minority, Mr Ocalan is the nearest they have to a national leader.
Mr Ocalan has a catalogue of crimes to answer for. His Kurdistan Workers' Party (PKK) has killed thousands in its long campaign of terror. His offer from the dock to negotiate peace if his life was spared looked like a cowardly bid to save himself. But the rebel leader still attracts huge support among Turkey's Kurds. A party suspected of links with the PKK dominated recent elections held in the country's south-east.
Hanging Mr Ocalan would be the culmination of Turkey's iron-fist policy against his rebel fighters. Ankara dismissed Mr Ocalan's peace offer, as it has dismissed his ceasefires in the past. The authorities steadfastly refuse to give ground on the Kurds' grievances, fearing the break-up of the Turkish Republic. Turkey does not even recognise the Kurds as a minority; Kurdish television is illegal, and the language cannot be taught in schools.
The Turkish government insists the country has no Kurdish problem. Anyone who challenges this line - whether Turkish or Kurdish - does so at their peril. Ismail Besikci, one of Turkey's most famous sociologists, is in prison. With more than 40 years left to serve, the 60-year-old will probably die in captivity. His crime was to write extensively about the Kurds and claim that their rights were being suppressed. Under Turkish law, his books made him a terrorist.
Akin Birdal, the country's leading human rights campaigner, dared to suggest that a peaceful solution might be found to the conflict with the PKK. A court found him guilty of inciting racial hatred: in his speech he had made a distinction between Turks and Kurds. He was sentenced to nine months. Neither Mr Birdal nor Dr Besikci is Kurdish.
Under Turkey's fearsome Anti-Terror Law, objective reporting of the conflict can be considered terrorist propaganda. In 1993, Oral Calislar, a famous newspaper columnist, published a series of interviews with Mr Ocalan. Mr Calislar believes the interviews were critical of the rebel leader. But when they were collected in book form, the journalist was sentenced to one year in prison.
"According to the law I'm a terrorist, but I'm only doing my job," says Mr Calislar. "I'm considered a terrorist not for expressing my own opinion, but for interviewing a guilty man."
Yet, despite the dangers, doubts over official policy are surfacing all the time. Mehmed's Book, a series of interviews with Turkish conscripts who fought against the PKK in the south-east, appeared in April. It raised serious questions about the effect of Turkey's savage campaign - which included the systematic burning of Kurdish villages - on the mental health of conscripts. The book was an instant success, running through four editions in two months. A few days ago, it was banned, and unsold copies were seized. A court found it had insulted the military, which is a criminal offence.
"If there is any criticism of the military in this book, it's not my criticism," says Nadire Mater, the journalist who wrote Mehmed's Book. "When these soldiers are on the mountains doing their military service, they are considered heroes. If there is any criticism, it comes from these `heroes'."
Now Ms Mater expects to be prosecuted. She could face 10 months in prison. According to the Paris-based organisation Reporters sans Frontieres, more than 90 journalists are currently imprisoned in Turkey, the vast majority for challenging the official line on the Kurdish issue.
Nobody knows what hanging Mr Ocalan may unleash. There were massive Kurdish riots across the world when he was captured in February, and several embassies were occupied, concentrating international attention for the Kurdish issue. The PKK was suspected of co-ordinating the protests. There are fears of similar scenes on Tuesday. Protests in Turkey were prevented only by mass pre-emptive arrests: more than 1,000 people were detained.
The PKK has threatened "total war" if its leader is hanged. Ankara dismisses the threat, saying the rebels are all but defeated. But in the aftermath of his capture, the PKK struck into the hearts of Turkish cities with a series of bomb attacks, stopping only after a personal plea from Mr Ocalan.
Mr Ocalan's lawyers say they will appeal to the European Court of Human Rights, whose decisions Turkey is bound by. Whether Turkey likes it or not, it looks as if the outside world will have a say in Mr Ocalan's fate.