Southern Africa is, for the first time in its existence, facing Islamist insurgency, a new type of conflict different from the types of conflicts it has experienced in the past. Despite these challenges, SADC has tried to silence the guns in the region through regional security mechanisms. However, the onset of an armed conflict in Mozambique, instigated by Islamist insurgent group Ahlu al-Sunnah wal-Jamaah, challenged SADC’s conflict management structures and the policy of non-interference. The Chapter’s objective is to assess SADC’s response to armed conflict in Mozambique through the Mutual Defence Pact and Protocol on Politics, Defence and Security Cooperation and highlight ambiguities that might lead to institutional inertia when implementing the Silencing the Guns agenda. The methodology is the text review of SADC documents, protocols, communiques, and summits applied in response to the conflict. The findings showed that SADC has a role and responsibility to ensure peace and security as part of the African Union’s Peace and Security Architecture. In response to this conflict, SADC’s group consensus gradually moved from reluctant statements to military involvement through the SADC Standby Brigade. It also appears that Article 6 and 7 of the Mutual Defence Pact are unclear about the meaning of non-interference and about collective security against non-state threats such that member states may opt for interventions from bilateral military assistance and private military companies. Non-interference as a southern African regional principle reinforced hesitancy by SADC member states and led them to avoid key African Union Peace and Security Council provisions in favour of regional actions. Mozambique also hesitated to involve SADC and the African Union. The prevarication created on both ends, allowed Rwanda and several other states and mercenary groups like Dyck Advisory Group and Wagner to be more involved. This case study shows that ambiguities around the principle of non-interference may create institutional inertia instead of the decisive implementation of the Silencing the Guns initiative.