A Charge Sheet Aimed at the Sea

On 29 September, Ethiopia’s army chief, Field Marshal Birhanu Jula, told the country that its soldiers were fighting forces “organised and allied to serve the interests of external forces”. He named Eritrea, Sudan and Egypt, and cast Eritrea as the go-between linking Cairo and Khartoum to Ethiopia’s rebels. All three denied it.

The geography is what matters. Two days earlier, Tigrayan forces had taken the town of Erebti in the Afar region and were pushing east towards Afdeera, deeper into the lowlands that border Eritrea and Djibouti and carry Ethiopia’s lifeline to the sea. Across the water, in mid-September, the Houthis had seized Yemen’s Red Sea coast down to the mouth of the strait. For the first time in a generation, both shores of the Bab el-Mandeb are war zones.

Two Wars, One Strait

The Bab el-Mandeb is a 32-kilometre-wide strait between Yemen and the Horn of Africa, through which about 12% of global trade normally passes. On its eastern shore, the Iran-aligned Houthis captured the port of Mocha, the town of Dhubab and Perim island in mid-September. Daily transits through the strait halved overnight, from 30 to 15, according to the tracking firm Kpler.

On the western shore, Ethiopia’s fragile peace has collapsed. The 2022 Pretoria agreement ended a war that killed an estimated 600,000 people. In September the Tigray People’s Liberation Front joined six other armed groups, including Amhara’s Fano militias and the Oromo Liberation Army, in an alliance that is now fighting in Tigray, Amhara and Afar — regions home to more than 38 million people. At least 150,000 people have fled their homes in Afar alone.

Behind both wars sits a long-running quarrel. Since Eritrea’s independence in 1993, Ethiopia has had no coastline. Prime Minister Abiy Ahmed has made sea access a national cause, telling parliament in February that “the Red Sea and Ethiopia cannot remain separated forever”, before insisting he had no plans for war.

Why This Is Now One Conflict

The usual way to read this map is as two separate crises that happen to sit close together: a Yemeni civil war that became a shipping crisis, and an Ethiopian civil war that became a humanitarian one. Navies deal with the first, mediators with the second. That division no longer holds.

Begin with the corridor. About 95% of Ethiopia’s trade moves along the road and railway from Addis Ababa through Afar to the port of Djibouti, for which Ethiopia pays around $1.5 billion a year. Tigrayan forces pushing into Afar are not just taking territory. They are threatening the one route by which a country of 130 million reaches the sea. That road ends at a port barely 100 kilometres from the Bab el-Mandeb, on the same waters the Houthis now overlook from Perim.

That threat changes Ethiopia’s calculus. A government that already believed being landlocked was a strategic error now has evidence of the cost: its only outlet can be squeezed by a rebellion it says is backed by Eritrea. And Field Marshal Birhanu’s statement does something earlier rhetoric did not. It frames Eritrea not as a neighbour that has a port Ethiopia wants, but as a party to the war. The Eritrean port of Assab sits on the same stretch of coast, less than 100 kilometres north of the strait, in territory that borders Ethiopia’s Afar region. Modern Diplomacy has argued that a dispute over Assab could threaten a global chokepoint. Ethiopia now has both a motive and a stated grievance.

The patrons overlap too. Egypt, locked in a 15-year dispute with Ethiopia over the Grand Ethiopian Renaissance Dam on the Nile, has built an alignment with Eritrea and Somalia. At a summit in Cairo in June, Egypt and Eritrea declared that littoral states bear “primary and exclusive responsibility” for Red Sea security — a pointed message to a landlocked Ethiopia. Sudan’s army-led government accuses Ethiopia of backing its enemy, the Rapid Support Forces paramilitary. And Israel’s recognition of Somaliland last December has turned Berbera, on the Gulf of Aden, into a potential front-line port in its contest with the Houthis.

The armed groups are linked as well. A UN panel of experts reported last year that the Houthis were supplying al-Shabaab in Somalia with weapons, drone technology and training. The Houthis’ new positions on Perim and the Zuqar-Hanish islands put their drones and missiles within easy reach of the African coast. Their capture of the eastern shore, which Modern Diplomacy has examined as a turning point for Red Sea shipping, now faces a western shore in flux.

The strongest objection is that these conflicts have separate causes and separate actors. The Houthis have no stake in Tigray. Abiy has repeatedly said he will not go to war for a port. Nobody is coordinating a single campaign. All true, and beside the point. Conflicts do not need a shared command to merge. They merge when they share terrain, patrons and consequences. A ship passing Perim is now exposed to whatever happens on both banks. A naval escort can deter missiles from Yemen; it cannot keep open a road through Afar or stop a land war over Assab. Western strategy still treats the Red Sea as a sea-lane to be policed. The threat now runs through the coast.

Three Ways the Strait Could Go

Base case (around 55%) — connected but contained. Ethiopia’s war grinds on through the dry season, with the Djibouti corridor disrupted but not severed. Addis Ababa keeps its accusations against Eritrea verbal. The Houthis hold the eastern shore, and traffic through the strait stays near half its normal level. Insurers price risk on both coasts, and Egypt’s Suez revenue keeps falling. The key assumption is that Ethiopia avoids opening a front with Eritrea while fighting its own rebels.

Downside case (around 25%) — the war reaches the coast. Rebels cut the Djibouti road, or Addis concludes that its only secure outlet runs through Assab and moves towards it, citing Eritrea’s alleged support for the rebellion. Egypt steps up backing for Asmara; the Houthis exploit the chaos on the African side. With fighting on both banks of a 32-kilometre strait, commercial traffic through the Bab el-Mandeb could fall close to zero, adding weeks to Asia–Europe voyages via the Cape and another leg to the global fuel and freight squeeze.

Upside case (around 20%) — a negotiated outlet. African Union and Gulf mediators revive the Pretoria framework, while a US-Iran ceasefire freezes the Houthi front. Ethiopia secures a long-term commercial port deal — in Djibouti, Berbera or, more ambitiously, Assab — that removes the pretext for war. This needs Saudi Arabia, which has grown closer to Eritrea, to act as broker rather than bystander.

Watch the Road, Not Just the Water

The Red Sea crisis has become a two-coast problem. With the Houthis on one shore and Ethiopia’s war pressing towards the other, the Bab el-Mandeb can no longer be secured from the water alone. Ethiopia’s quest for the sea has turned an African civil war into a maritime one.

Watch the Djibouti corridor. If fighting in Afar reaches the road and railway between Addis Ababa and Djibouti, Ethiopia’s incentive to seek another route to the sea — through Eritrea — rises sharply, and the two coasts of the strait become one battlefield.

For three years the world has guarded the Red Sea from the water. The next threat to it may arrive by road.