Why did the Nkomati Accord fail to end Renamo’s activities?

The Nkomati Accord, signed in 1984 between Mozambique and South Africa, failed to end the activities of the Renamo insurgency primarily because the agreement was violated by South Africa.12

Under the terms of the accord, both nations pledged to cease support for each other's opposition movements—specifically the African National Congress in South Africa and Renamo in Mozambique. However, because South Africa continued its covert support for the insurgency, the agreement did little to curb Renamo’s campaign of economic sabotage and violence against the rural population. Consequently, the conflict persisted until the government of Mozambique and Renamo leadership reached a formal peace agreement in 1992.123