Why the world is worried about the looming danger of an all-out Ethiopia-Eritrea war

After weeks of clashes and military advances by both sides, a full-scale war between Ethiopia and Eritrea is looming as an increasingly dangerous possibility, triggering fears of another crisis in the Horn of Africa.

Ethiopian troops, backed by tanks and heavy weapons, have rapidly approached the Eritrean border in recent days, while Eritrea reportedly sent thousands of its own soldiers across the border into northern Ethiopia. Both sides have expelled each other’s diplomats and severed relations, accusing each other of plotting war.

U.S. Secretary of State Marco Rubio became the latest diplomat to plead for peace this week. In a phone call with Ethiopian Prime Minister Abiy Ahmed, he cited the “heightened tensions” and urged all countries to “avoid cross-border incursions.” The region cannot tolerate more conflict, he told Mr. Abiy, according to a State Department readout Wednesday.

Mr. Rubio was referring to the ongoing wars and insurgencies that are already inflicting massive damage in Sudan, South Sudan and Somalia. Those conflicts are increasingly entangled and spilling across borders, with Sudan and Eritrea accusing Ethiopia of providing military bases and drones for the Rapid Support Forces, a paramilitary group fighting a civil war against the Sudanese Armed Forces.

Why the surging conflict in northern Ethiopia could spill across borders

Canada added its own warning Thursday, saying it was deeply concerned about the danger of regional escalation. In a statement, Global Affairs Canada called for an easing of the “inflammatory cross-border rhetoric.”

Ethiopia alleges that Eritrea is supporting the Tigray People’s Liberation Front (TPLF), which launched a rebellion last month in the northern Ethiopian region of Tigray. The TPLF seized three airports and marched into neighbouring Afar region, with the support of other rebel militias, but were driven back by Ethiopian forces. Hundreds of people have reportedly been killed in the fighting since last month.

The Ethiopian army, after recapturing most of Tigray’s cities and towns in the past three weeks, has advanced northward to the Eritrean border, leaving the two national armies confronting each other across a frontier where the two countries have battled in the past.

Ethiopia alleges that Eritrean troops have crossed the border and advanced as far as 60 kilometres into Ethiopian territory – a claim supported by many media reports and independent analysts.

Much of the international concern is sparked by memories of the Tigray war from 2020 to 2022, when an estimated 600,000 civilians died from violence or starvation while the Ethiopian army battled Tigrayan insurgents. The same region was the site of a brutal conflict between Ethiopia and Eritrea in the late 1990s, with hundreds of thousands of troops dying in trench warfare and human wave attacks.

Since August, Ethiopia has launched dozens of drones strikes in Tigray, including reported attacks on Eritrean troops and Tigrayan rebels. The rebels have retreated to the mountains and rural areas of Tigray but remain active.

“If war breaks out, it could be the biggest since the Russia-Ukraine war,” said Kjetil Tronvoll, a Norwegian professor of peace and conflict studies who specializes in Eritrea and Ethiopia. “It might even surpass it in terms of the number of combatants.”

In an interview with The Globe and Mail, Prof. Tronvoll estimated that several hundred thousand Ethiopian and Eritrean troops are now amassed at the border, within a few kilometres of each other. The two armies may be closest to direct conflict at the border town of Zalambessa, the site of a major battle between the two sides in the 1998-2000 war.

In recent months, Ethiopia has been rapidly building its army with fresh troops and a growing arsenal of heavy weaponry, including Chinese artillery and armoured vehicles, newly produced drones and other military equipment flown into the country, Prof. Tronvoll said. “It’s been a huge arms race.”

Ethiopian troops are now within 80 kilometres of the Eritrean port city of Assab, widely believed to be a key target of any cross-border incursion. Ethiopian military and political lobbyists have repeatedly demanded that Assab be Ethiopian again, after losing it in 1993 when Eritrea gained independence. Mr. Abiy has said for years that his landlocked country needs a port on the Red Sea.

In a report this week, the International Crisis Group says the two countries “stand perilously close to all-out war,” with heavy fighting moving close to the border. Tensions have reached a “fever pitch” and the two countries seem “poised to engage in frontal combat,” the report says.

“Outright conflict between Ethiopia and Eritrea would likely spread to the Red Sea, disrupting the African side of this strategic waterway,” the report adds, warning that the conflict could drag in countries such as Sudan, Egypt, Saudi Arabia and the United Arab Emirates.

The United Nations Security Council discussed the Ethiopia-Eritrea conflict in a closed-door session Tuesday, but no solutions emerged. Both countries sent letters to the Security Council, accusing the other of aggression. Both insisted that their military manoeuvres were merely designed for self-defence.