Explainer| How Ethiopia’s war became a regional crisis threatening the Horn of Africa

The war raging in northern Ethiopia has expanded from an internal crisis for Addis Ababa into a wider regional conflict. From its outbreak on Sept. 23 until now (Oct. 13), the intensifying fighting has steadily narrowed the maneuvering room for the region’s key players.

In less than three weeks, an armed coalition took shape with the explicit aim of ousting Ethiopian Prime Minister Abiy Ahmed, triggering renewed combat across Tigray. After Addis Ababa accused Cairo and Khartoum of backing anti-government forces, Egypt and Ethiopia carried out reciprocal expulsions of diplomats, followed by Eritrea severing diplomatic ties with its Ethiopian neighbor.

For Egypt, concerns extend well beyond Addis Ababa’s accusations or the protracted dispute over the Grand Ethiopian Renaissance Dam. Landlocked since Eritrea gained independence in 1993, Ethiopia views maritime access as a strategic imperative. In January 2024, Addis Ababa signed a memorandum of understanding with Somaliland that, according to official Ethiopian state media, allows it access to develop a port and establish a naval base on the Red Sea in exchange for potentially recognizing the breakaway region. Mogadishu rejected the deal outright, condemning it as a flagrant violation of Somalia’s sovereignty and territorial integrity.

A month after the deal was signed in 2024, and again in February 2026, President Abdel Fattah El-Sisi and Somali President Hassan Sheikh Mohamud reaffirmed that securing the Red Sea and the Gulf of Aden remains the exclusive responsibility of littoral states, highlighting Egypt and Somalia’s strategic positions guarding the sea’s northern and southern gateways.

For Cairo, the fighting in Ethiopia directly intersects with two core national security interests: Nile water security to the south, and the stability of the Red Sea and the Suez Canal to the east and north.

What is happening in Ethiopia?

On Sept. 20, seven Ethiopian political and armed factions announced the creation of the “Ethiopian Peoples’ Forces Alliance for Survival,” declaring their goal to overthrow Abiy Ahmed’s government and establish a transitional administration.

This war erupted nearly four years after the African Union-brokered Pretoria Agreement of November 2022, which ended a two-year war between the federal government and the Tigray People’s Liberation Front (TPLF) without resolving core disputes. Key unresolved issues include the disarmament and reintegration of fighters, the return of displaced communities, the fate of contested territories between Tigray and Amhara, and the long-term governance structure of the region.

Led by Zemene Kassie, head of the Amhara Fano National Movement (AFNM), the coalition brings together the TPLF, the Oromo Liberation Army, and factions from other regions. The alliance presents a striking irony: during the 2020-2022 war, AFNM militias fought alongside Ethiopian federal forces against Tigrayan forces, and both sides remain locked in bitter territorial disputes over western Tigray. For now, however, they have shelved disagreements over territory, identity, and state structure to unite against a common adversary: the Abiy Ahmed administration.

Within three days of the coalition’s formation, Tigrayan forces seized the airport in Mekelle, the regional capital, along with airports in Aksum and Shire, halting civil aviation. Clashes quickly spilled into the neighboring Amhara and Afar regions. The push into Afar was critical, as it straddles the Addis Ababa–Djibouti corridor, the primary economic lifeline for landlocked Ethiopia.

Meanwhile, the “Tigray Peace Force,” a faction opposed to the current regional leadership, aligned itself with the federal military. Heavy artillery shelling and airstrikes escalated the fighting against the backdrop of widespread communications blackouts. On the night of Sept. 30 to Oct. 1, blasts were heard in Addis Ababa amid reports that opposition forces had deployed drones.

By Oct. 4, federal troops and allied forces recaptured Mekelle following a withdrawal by Tigrayan forces. Yet the fighting persisted, with government troops pushing northward toward the Eritrean border.

How did Egypt enter the crisis?

As clashes expanded, the head of the Ethiopian National Defense Force, Birhanu Jula, accused Egypt, Sudan, and foreign powers of supplying anti-government fighters, asserting that they could not make territorial gains “unless they received support and supplies” from abroad. Cairo denied any involvement, affirming that it was monitoring developments without harboring hostility toward Ethiopia. Sudan similarly rejected the allegations.

On Oct. 1, Ethiopia gave an Egyptian diplomat 48 hours to leave the country, prompting Cairo to respond with a reciprocal expulsion. Simultaneously, Addis Ababa shuttered its embassy in Asmara and expelled 10 Eritrean diplomats, leading Eritrea to sever diplomatic relations.

Four days later, on Oct. 4, President El-Sisi hosted a quadrilateral summit in New Alamein City with the Chairman of Sudan’s Transitional Sovereignty Council Abdel Fattah Al-Burhan, Eritrean President Isaias Afwerki, and Somali President Hassan Sheikh Mohamud.

The joint declaration issued after the summit underscored the shared priorities binding the four nations: supporting Somalia’s sovereignty and territorial integrity, rejecting any recognition of Somaliland, asserting that Red Sea governance is the exclusive responsibility of littoral states, and opposing unilateral measures that harm existing Nile water use for the two downstream countries.

Why do Cairo and Addis Ababa’s interests clash?

For over a decade, tensions between Egypt and Ethiopia have steadily mounted over the Grand Ethiopian Renaissance Dam. Cairo has consistently demanded a legally binding agreement governing the dam’s filling and operation, while Ethiopia has pressed ahead unilaterally.

In recent years, Ethiopia’s drive to secure direct Red Sea access has further strained relations. Ever since Eritrea’s 1993 independence stripped Ethiopia of its coastline, Addis Ababa has relied on ports in neighboring countries, particularly Djibouti. Prime Minister Abiy Ahmed has repeatedly framed maritime access as vital to national security and economic growth, asserting this October that modernizing Ethiopia cannot be achieved without a seaport, while maintaining that his country seeks access through peaceful diplomacy.

In January 2024, official Ethiopian state media reported that Addis Ababa signed a memorandum of understanding with the breakaway territory of Somaliland, aimed at securing Red Sea access to build a naval base and commercial port facility.

Somalia denounced the agreement as an act of aggression against its sovereignty, with President Mohamud warning that his country would defend itself if Ethiopia moved forward with the naval base agreement.

Following the MoU, Cairo sharply accelerated its defense and security engagement in the Horn of Africa. Egypt signed a military cooperation protocol with Mogadishu in August 2024, subsequently delivering its first arms shipments to Somalia in over four decades. By October of that year, Egypt, Eritrea, and Somalia agreed to boost trilateral security coordination and bolster Somali state institutions.

Egyptian rapprochement with Mogadishu has deepened further. Alongside the activation of the military cooperation agreement and Egypt’s scheduled participation in the African Union mission in Somalia, El-Sisi and his Somali counterpart emphasized again in February that securing the Red Sea and the Gulf of Aden is solely the responsibility of littoral states.

Minister of Foreign Affairs Badr Abdelatty reaffirmed this position during talks with Eritrea, stressing Egypt’s categorical rejection of attempts by non-littoral states to establish security footprints or impose maritime arrangements in the Red Sea.

Analysts note that Cairo has long opposed Ethiopian ambitions to establish a naval presence on the Red Sea, viewing it as a direct challenge to its security interests along the vital maritime corridor running from the Bab Al-Mandeb Strait to the Suez Canal. These concerns grew more acute after recent shipping disruptions underscored how southern maritime threats can choke Suez Canal traffic and toll revenues, creating an additional point of leverage alongside Nile issues.

Why did the crisis spill into Eritrea?

During the 2020-2022 Tigray war, Eritrea fought as a close military ally of Abiy Ahmed’s government against the TPLF, but the alliance subsequently collapsed.

Eritrea argues that Ethiopia’s push since 2023 for a “sovereign outlet” to the Red Sea is aimed at the Eritrean port of Assab, representing an existential threat to its sovereignty and a bid to seize territory by force. Abiy Ahmed, by contrast, maintains that Ethiopia is pursuing maritime access through peaceful negotiation rather than conflict.

As federal troops pushed north during the latest round of fighting, Addis Ababa accused Eritrean forces of crossing into Tigray, advancing up to 60 kilometers, according to Ethiopian claims.

Eritrea denied mounting an invasion, accusing Ethiopia of manufacturing a pretext for war. On Oct. 10, Asmara appealed to the UN Security Council, demanding deterrent measures against Addis Ababa under Chapter VII of the United Nations Charter.

Ethiopian forces and allied militias advanced into the border town of Adigrat, amid reports of Ethiopian drone strikes targeting withdrawing Eritrean units near the city.

Within days, relations deteriorated from rhetorical barbs over proxy support into direct military friction along the frontier, marking the most dangerous escalation between the two neighbors in years.

Where does Sudan stand?

Historical friction between Sudan and Ethiopia centers on three interconnected flashpoints: chronic border disputes, water security, and reciprocal backing of rebel factions. The fertile agricultural borderlands of Al-Fashaga remain the epicenter of territorial friction. While Sudan’s sovereignty was established under a 1902 treaty, Ethiopian farmers and militias controlled parts of the area for decades until the Sudanese military reclaimed most of the pocket in late 2020.

The same 1902 treaty also underpins the water dispute, having ceded the Benishangul region to Ethiopia on condition that no infrastructure obstructing the Blue Nile’s flow be built without Khartoum’s consent. Sudan views the unilateral filling and operation of the Grand Ethiopian Renaissance Dam as a direct violation of that accord, while bilateral mistrust has been further entrenched by decades of mutual support for opposition and insurgent groups.

Khartoum’s stance on the Red Sea was clearly articulated in the El Alamein declaration, signed by Al-Burhan alongside the leaders of Egypt, Eritrea, and Somalia. The declaration affirmed that Red Sea governance is reserved strictly for littoral states, reiterated its refusal to recognize Somaliland, and backed downstream rights to Nile waters.

The unfolding crisis has thus brought together diverse regional actors with distinct grievances against Ethiopia: Egypt over the Nile and Red Sea security, Eritrea over territorial sovereignty and its ports, Somalia over national integrity, and Sudan over war, borders, and water.

This convergence makes the resumption of warfare in Tigray far more dangerous than an internal skirmish. The conflict has become a geopolitical junction where Nile waters, borders, ports, and maritime security collide, in a region where any disruption ripples from the Nile basin and Sudan’s southern borders directly to the northern entrance to the Suez Canal.