A recently resurfaced account details a shocking reversal of fortune following Algerian independence in 1962. The “Algerian army of the frontiers,” which had been sheltered and supplied by Tunisia during its struggle, turned against its host nation immediately after independence. This article explores this “great betrayal” of the summer of 1962, uncovering a previously less-discussed conflict between the two North African neighbors. The Algerian forces, once beneficiaries of Tunisian hospitality, instigated hostilities against those who had aided their cause. This unexpected aggression marked a significant and troubling start to the relationship between independent Algeria and Tunisia. The story highlights a complicated period with lasting implications for regional dynamics. Kapitalis originally published the account, bringing renewed attention to this historical event.