Somalia African Union ATMIS mission impact on security and politics

MOGADISHU, Somalia — The African Union Transition Mission in Somalia (ATMIS) was designed to help Somalia’s security forces take over responsibility for fighting al-Shabaab and holding territory. As ATMIS drew down and ultimately ended, its impact became visible not only on the ground in security operations, but also in how political authority is exercised across Somalia’s federal and state system.

ATMIS replaced the long-running AMISOM mission and was closely tied to a wider international strategy: support Somali forces while reducing external troop presence. In 2025, ATMIS was replaced by the African Union Support and Stabilisation Mission in Somalia (AUSSOM), marking a shift from “transition” to “support and stabilisation.”

Background: What ATMIS Was Built to Do

ATMIS was established to support Somalia’s move toward a Somali-led security system. The mission’s core logic was straightforward: external forces could help provide security, training, and operational support while Somali forces became capable of leading security efforts themselves.

In practice, ATMIS operated alongside the Somali state-building process, which has been shaped by:

• • Clashing security priorities between areas controlled by the federal government and those influenced by local actors or insurgents.

• • Complex governance involving the federal government, regional states, and institutions with uneven capacity.

• • Militant violence by al-Shabaab, which continued to challenge government control in multiple regions.

What Happened

ATMIS ran through a drawdown period aimed at transferring security responsibility to Somali forces. Key milestones included the widening international support for the transition path and, later, the formal step to replace ATMIS with AUSSOM.

Among the main documented steps:

• • End of the ATMIS transition mandate: The UN Security Council endorsed the move to replace ATMIS with AUSSOM, with operations starting 1 January 2025.

• • Shift in mission focus: The successor mission was positioned to provide support and stabilisation while continuing to back Somali efforts against al-Shabaab and affiliates.

• • Institutional handover: The transition process included support activities tied to Somali police and security structures, alongside the gradual reduction of foreign troop presence.

Why It Matters

The ATMIS mission matters for two linked reasons: security outcomes and political leverage.

Security: Changing the Model of External Support

ATMIS was built around transition. That meant external forces were not only fighting or deterring threats, but also enabling Somali forces to carry out security tasks over time.

After the mission’s drawdown and replacement:

• • The operational burden increasingly shifted to Somali security institutions.

• • Security stability became tied more closely to Somali capacity, coordination, and readiness in areas where al-Shabaab remained active.

• • Support functions continued under the successor mission, but with a different framing than “transition to Somali takeover.”

Politics: Security Presence and Authority to Govern

In fragile states, security control often shapes political power. ATMIS did not replace Somalia’s political system—but its presence and drawdown had practical consequences for governance.

As ATMIS transitioned out, political questions that had been partly cushioned by external security assistance moved closer to the center of domestic debate, including:

• • How Somali institutions manage security responsibilities across different regions.

• • How federal-state relations align when security needs differ by location and threat level.

• • How political legitimacy is tested when territory and services face continued pressure from armed groups.

Key Facts

• • ATMIS role: Support the transition to Somali-led security responsibility while helping degrade al-Shabaab’s capability.

• • Replacement: The UN Security Council endorsed replacing ATMIS with AUSSOM.

• • Start date of successor mission: 1 January 2025.

• • Core transition idea: External troop presence would reduce over time as Somali forces took over more duties.

• • Political impact channel: Security responsibility increasingly affects governance, legitimacy, and federal-state coordination.

Questions About Somalia’s Next Security Phase

1. 1. How effectively can Somali forces coordinate security tasks across regions after the end of ATMIS transition support?

1. 1. What balance will the successor mission maintain between stabilisation assistance and Somali command over operations?

1. 1. How will security priorities influence domestic political negotiations between the federal government and regional stakeholders?

Conclusion

ATMIS was a mission built for handover: enabling Somali security institutions while reducing the external footprint over time. Its impact on Somalia’s security landscape was closely linked to the wider political challenge of governing territory under sustained insurgent pressure.

With the shift from ATMIS to AUSSOM in January 2025, Somalia’s security and political trajectory entered a new phase—one in which stabilisation support continues, but where the central question remains whether Somali institutions can sustain security gains and translate them into durable governance.