To succeed in tackling al-Shabaab, the new peace support operation needs appropriate resourcing and protection from regional tensions.

Seventeen years after the first African Union (AU) mission was deployed in Somalia to degrade the violent extremist group al-Shabaab, the country is set to have a third peace support operation starting on 1 January 2025.

This month, the AU Peace and Security Council endorsed a proposal to form the AU Support and Stabilization Mission in Somalia (AUSSOM). It will take over from the AU Transition Mission in Somalia (ATMIS), which replaced the country’s first mission (AMISOM) in April 2022.

The new deployment still requires approval from the United Nations Security Council, which ultimately authorises peace missions based on Chapter VIII of the UN Charter. The council’s Resolution 2748 (2024) indicated the possibility of the new mission, pending a report on its design by 15 November.

Launching AUSSOM raises several questions – mainly how it differs from its predecessors, if it can do better against al-Shabaab, and successfully hand over security responsibility to the Somali Security Forces.

AUSSOM will be deployed in a changed geopolitical environment, marked by escalating tensions between Somalia and Ethiopia, which contributes troops to ATMIS. The two are at loggerheads over the January memorandum of understanding between Ethiopia and Somaliland, a self-declared independent state. The details of the agreement haven’t been made public, but it allegedly grants Ethiopia sea access and a military base in return for political recognition of Somaliland.

Questions about AUSSOM are valid. While the mission may help renew continental and international support for counter-terrorism in Somalia, protecting it from regional tensions will be essential.

Previous missions enabled Somalia to achieve vital security and state-building gains, including consolidating a federal governance system and conducting elections. Somalia became an East African Community member in 2023 and joins the UN Security Council as a non-permanent member for 2025-26.

AMISOM and ATMIS, alongside international partners, also helped launch offensive operations against al-Shabaab and develop the Somali Security Forces’ capacity – as a result, liberating several territories and strategic towns.

The new mission differs from its predecessors in its mandate and operational modalities. Due to Ethiopia-Somalia tensions, Ethiopia probably won’t contribute troops, while Egypt likely will.

Previous missions have struggled with multiple, sometimes conflicting, roles and expectations. Unlike them, AUSSOM will have a more defined supportive role, with more pronounced functions for the Somali Security Forces.

In contrast to ATMIS, AUSSOM should have a more realistic, longer time frame. ATMIS was given under three years to degrade al-Shabaab by supporting offensive military operations and building capacity in the Somali Security Forces. AUSSOM’s priority will be to bolster operations of the Somali Security Forces and carry out capacity building. Unlike earlier missions, it has an explicit mandate to protect civilians under immediate threat of physical violence. AUSSOM will have five years to complete its work (2025-29).

The new mission will follow a backup and urban-based operation approach, with a force strength of 11 146 troops, 85 civilians and 680 police officers. This is less than the maximum strength for AMISOM (about 22 000) and ATMIS (19 626).

Authorised strength of AMISOM, ATMIS and AUSSOM missions in Somalia, 2007-2028

Source: Multiple UNSC resolutions

Several challenges that constrained both AMISOM and ATMIS will probably also confront AUSSOM. Al-Shabaab remains a regional threat, adapting to counter-terrorism efforts by the AU missions and Somali government. Using asymmetric warfare tactics, it continues its deadly attacks, endangering major supply routes. The group also administers territories, particularly in southern Somalia. Alliances with international terrorist groups, like al-Qaeda, have enhanced al-Shabaab’s capabilities in Somalia and the region.

AMISOM and ATMIS have struggled to subdue al-Shabaab due to limited and unpredictable funding and logistical challenges. One problem with ATMIS has been its phased withdrawal of personnel tied to specific benchmarks. While this process is essential for an orderly exit, the timeline is unrealistic and doesn’t reflect changes in the conflict landscape.

Omar Mahmood, the International Crisis Group’s Eastern Africa Senior Analyst, says, ‘The political ambitions around the transition have consistently not matched ground realities,’ including the security conditions and progress in security force generation. This has resulted in delays across almost all of ATMIS’ phases.

Notably, both AMISOM and ATMIS were military-heavy and not sufficiently able to tackle the socio-political drivers of instability. They also struggled to combine capacity building, governance support, and the international coordination of political and security actors.

Somalia certainly needs a follow-on mission to avoid a security vacuum, and the decision to replace rather than renew ATMIS was based on several issues. AUSSOM addresses ATMIS’ mismatch between mandate and capacity, its unrealistic drawdown, and its flagging international support.

The new mission’s success hinges on several critical factors. The first is an orderly transition of ATMIS to AUSSOM that maintains current gains.

Second is AUSSOM’s contributions to implementing the Somalia Security Sector Development Plan adopted last year. The six-year plan, endorsed by international partners, proposes a comprehensive approach to defeating al-Shabaab and achieving sustainable peace and security. The plan includes strengthening security in urban centres, countering terrorism funding and extremist ideology, and enhancing strategic communication. AUSSOM must adopt a comprehensive approach beyond military activities to support the plan.

Third, AUSSOM’s operational capability must be aligned with its mandate. Adequate financing is needed, along with qualified personnel and resources such as attack helicopters. Effective coordination with various partners and stakeholders will also be crucial.

The fourth vital success factor will be managing the region’s geopolitical tensions, especially considering Ethiopia and Somalia’s diplomatic row. While authorising AUSSOM is important, the UN and AU should proactively protect the mission from political repercussions, including by facilitating Ethiopia-Somalia talks.

Written by Meressa K Dessu, Senior Researcher and Training Coordinator, ISS Addis Ababa; Dawit Yohannes, Project Manager and Senior Researcher, ISS Addis Ababa; and Tsion Belay Alene, Researcher, ISS Addis Ababa