Why does Okonkwo and his tribe decide Ikemefuna must die? Is this barbaric and senseless, or are there underlying reasons?

The Oracle has decreed that Ikemefuna must be killed as part of the retribution for the woman killed three years prior in Mbaino. From a Western perspective, this makes little sense. Poor Ikemefuna has no hand in his own fate. This, however, is a different culture. The trade of children and women for crimes between tribes could broker peace. Is this a better alternative to war?