At best, the dramatic arrest of Laurent Gbagbo, after weeks holed up at the presidential palace in Abidjan, marks the transfer of power that should have happened peacefully five months ago. Mr Gbagbo's refusal to concede an election declared to have been won by his rival, Alassane Ouattara, led to a protracted stand-off, which degenerated into increasingly vicious fighting. The recent intervention of French troops, at the request of UN peace-keepers, spelt the beginning of the end.

So far, so good. A final shoot-out, it appears, was avoided. Mr Gbagbo was taken to the headquarters of his rival and said to be in good health. The intention of the Ouattara camp is that he should stand trial. And this is where the next stage of complications begin. If Mr Gbagbo is to be tried in Ivory Coast, it is crucial that the charges derive from genuine crimes, not a desire for political revenge, and that any trial is conducted in full compliance with international norms. Mr Ouattara and his supporters must resist the temptation to impose victor's justice.

Observing the formalities, however, may be simpler than the task facing Mr Ouattara as president. For while he won a clear electoral victory – by 54 per cent to 46 per cent, as confirmed by the relevant commission and the UN – it was not so decisive as to overcome the country's deep political and economic fault-lines. What has happened since will only have exacerbated those divisions, with violence and atrocities reported on either side. Add the damage to an already ailing economy from the months of conflict, and Mr Ouattara may find it hard to impose his authority, let alone foster the essential spirit of reconciliation.

The precise details of Mr Gbagbo's capture will also play a part. The French yesterday denied that he had been seized by their special forces, insisting that it was troops loyal to Mr Ouattara who had received his surrender. If this turns out to be untrue – or if it is widely disbelieved – Mr Ouattara risks being seen less as the legitimate winner of an election than as the creature of the former colonial power. That would make the start to his presidency even less auspicious than it already seems.