Ethiopia and Eritrea: Why Their Relationship Keeps Returning to Conflict

Ethiopia and Eritrea have moved from war to frozen hostility, from a celebrated peace deal to military partnership, and now back to diplomatic rupture and renewed security tensions. The pattern can seem contradictory until the relationship is viewed through three enduring issues: the unresolved legacy of the 1998–2000 border war, the strategic rivalry surrounding Ethiopia’s loss of Red Sea access after Eritrean independence, and the changing balance of power inside Ethiopia—particularly the rise and fall of the Tigray People’s Liberation Front (TPLF).

The two countries formally ended their state of war in 2018, but the agreement did not eliminate those underlying strategic differences. Instead, Ethiopia and Eritrea found temporary common ground when their interests aligned against the TPLF during the 2020–2022 Tigray war. That alignment subsequently broke down. By October 2026, Ethiopia had closed its embassy in Eritrea and Eritrea had severed diplomatic relations, while renewed fighting in Tigray had raised fears that the bilateral dispute could once again become militarized.

The relationship in one timeline

The relationship began with a separation that never stopped shaping it

Modern Ethiopia–Eritrea relations cannot be understood without Eritrea’s independence.

Eritrea was incorporated into Ethiopia after the Second World War and later became the scene of a prolonged independence struggle. After decades of armed conflict, Eritrea formally became independent in 1993.

Independence transformed the relationship but did not remove the strategic consequences of separation.

Ethiopia, a country without a coastline, lost direct access to the Red Sea. Eritrea inherited the coastline and ports that had previously been connected to the Ethiopian economy.

For Eritrea, independence was the foundation of sovereignty. For Ethiopia, becoming landlocked created a lasting strategic and economic constraint.

That difference still matters today.

Ethiopia has subsequently relied heavily on neighboring countries—particularly Djibouti—for maritime trade. Its dependence on external ports has helped make Red Sea access a recurring issue in Ethiopian foreign policy.

The 1998–2000 border war

The first major post-independence rupture came in 1998.

The immediate dispute centered on territory around Badme, but the causes were broader. The two governments had unresolved disagreements over their border, economic relations, currency and trade, while the relationship between Ethiopia’s ruling leadership and Eritrea’s government had deteriorated.

A local territorial confrontation developed into a conventional war between the two states.

The conflict was exceptionally destructive. Tens of thousands of people were killed, and large numbers were displaced. Both governments mobilized substantial military forces, while the fighting spread across several sections of the border.

The war ended through the Algiers peace process. A cessation-of-hostilities agreement was signed in June 2000, followed by the Comprehensive Peace Agreement in December. The agreement created a Boundary Commission tasked with delimiting and demarcating the border and provided for binding arbitration over claims arising from the conflict.

But ending the fighting did not produce normal relations.

The border decision became the center of a frozen conflict

In 2002, the Eritrea-Ethiopia Boundary Commission issued its delimitation decision. The United Nations records that the parties had accepted the decision as final and binding under the Algiers framework.

Implementation nevertheless became politically contentious.

The result was a prolonged state often described as “no war, no peace.” The two countries did not return to full-scale war, but diplomatic relations remained hostile, the border was heavily militarized and meaningful economic integration did not develop.

The disagreement was therefore no longer simply about where a line should be drawn on a map. It became embedded in each government’s broader security calculations.

For Eritrea, a powerful Ethiopia represented a potential security threat.

For Ethiopia, Eritrea was a hostile neighbor on its northern frontier and a state with close connections to opponents of the Ethiopian government.

That mutual suspicion would become particularly important after Ethiopia’s internal political order changed.

Why the TPLF mattered so much

For much of the period after 1991, the TPLF was one of the most powerful forces in Ethiopian politics.

The TPLF was a leading component of the Ethiopian People’s Revolutionary Democratic Front (EPRDF), the coalition that governed Ethiopia after overthrowing the Derg regime in 1991.

Eritrean President Isaias Afwerki and the TPLF had once been partners in the struggle against the Derg. Their relationship subsequently deteriorated dramatically.

The 1998–2000 war transformed the TPLF and Eritrean leadership into bitter adversaries.

This history became crucial in 2018.

When Abiy Ahmed became Ethiopia’s prime minister, he moved rapidly to change the political balance inside the country. The TPLF lost its dominant position at the federal level and eventually withdrew to its regional stronghold in Tigray.

From Eritrea’s perspective, this was a major strategic change.

The Ethiopian leadership that had been closely associated with the TPLF was being replaced by a government willing to engage directly with Asmara.

Why the 2018 peace deal happened so quickly

The speed of the 2018 rapprochement was remarkable.

Abiy and Isaias had powerful reasons to test a new relationship.

For Ethiopia’s new prime minister, ending the confrontation with Eritrea offered a way to remove a major external security problem while pursuing a broader political transformation.

For Eritrea, the decline of the TPLF’s influence in Addis Ababa created an opportunity to improve relations with Ethiopia without dealing with the political force that Asmara regarded as its principal Ethiopian adversary.

In July 2018, the two governments signed the Joint Declaration of Peace and Friendship. It stated that the state of war had ended, committed the countries to political, economic, social, cultural and security cooperation, and provided for the implementation of the boundary decision.

Diplomatic relations resumed, borders reopened and transport links were restored.

The agreement was internationally celebrated. The United Nations described the September 2018 Saudi-brokered peace signing as a historic development, while Abiy later received the 2019 Nobel Peace Prize partly for his efforts to resolve the border conflict with Eritrea.

But the new relationship had an important weakness: the two governments had achieved political reconciliation faster than they had built durable institutions for managing their underlying strategic differences.

The unexpected alliance: Ethiopia, Eritrea and the Tigray war

The 2020 Tigray conflict temporarily transformed the relationship again.

In November 2020, fighting broke out between Ethiopia’s federal government and the TPLF-led authorities in Tigray.

Eritrea entered the conflict on the side of the Ethiopian federal government.

This was a striking reversal of regional history. The former enemies of the TPLF were now fighting on the same side, while Tigrayan forces were again confronting Eritrean troops across the same broader frontier where the two states had previously fought.

Eritrean forces operated inside Tigray during the war, and international investigations documented serious allegations of abuses against civilians. Eritrea disputed allegations concerning its conduct.

The partnership nevertheless served the immediate strategic interests of both governments.

For Addis Ababa, Eritrean military involvement strengthened the federal government’s position against the TPLF.

For Asmara, the war offered an opportunity to confront the TPLF, its longstanding adversary, in a conflict taking place largely on Ethiopian territory.

The alliance demonstrated something important about Ethiopia–Eritrea relations: shared opposition to a common adversary could overcome decades of hostility—but it did not necessarily resolve the reasons that had produced that hostility in the first place.

The 2022 peace agreement changed the calculation again

The Tigray war ended its main phase with the November 2022 Pretoria agreement between the Ethiopian government and the TPLF.

Eritrea was not a party to that agreement.

That distinction mattered.

The Tigray settlement created a new political framework inside Ethiopia while leaving questions about Eritrean troops, territorial disputes and regional security unresolved.

Ethiopia now had a federal government seeking to consolidate peace inside the country. Eritrea, meanwhile, faced a new strategic environment in which its former military partner was negotiating directly with the TPLF.

The relationship that had been useful during the war therefore became harder to sustain after the war.

The Red Sea question brought the underlying strategic problem back

One of the most important reasons tensions returned is Ethiopia’s interest in reliable access to the Red Sea.

Ethiopia has been landlocked since Eritrea’s independence. Its international trade depends heavily on access through neighboring states, particularly Djibouti.

Prime Minister Abiy has increasingly described maritime access as strategically important to Ethiopia’s economic future. In October 2026, he again argued that Ethiopia needs Red Sea access and said Addis Ababa would pursue it through negotiation and mutual benefit.

For Eritrea, however, the issue has a very different meaning.

Eritrea possesses a long Red Sea coastline and strategic ports, including Assab. Any Ethiopian effort to obtain a long-term maritime foothold therefore has direct implications for Eritrea’s sovereignty and security.

This does not automatically mean that Ethiopia intends to seize Eritrean territory. Ethiopian officials have emphasized negotiation. But the strategic asymmetry is obvious: Ethiopia needs dependable maritime access, while Eritrea controls territory that could provide it.

That makes Red Sea access one of the most important structural issues in the relationship.

Why Ethiopia and Eritrea keep interpreting each other as security threats

The recurring problem is a classic security dilemma.

Each country can describe its actions as defensive while the other sees them as preparation for confrontation.

Ethiopia’s desire for maritime access can be presented as an economic necessity. Eritrea can interpret the same objective as a potential threat to its territorial security.

Eritrea’s military posture can be described as necessary for national defense. Ethiopia can view the same posture as evidence that Asmara is preparing to interfere in Ethiopian affairs.

Support for political actors across the border can similarly be interpreted in opposite ways.

This is why agreements between the two governments have repeatedly depended heavily on the political relationship between leaders. When interests converge, cooperation can move rapidly. When the strategic relationship deteriorates, there are relatively few institutional mechanisms capable of containing the disagreement.

Why Tigray remains central even after the war

Tigray sits directly between the two countries and has historical, political and military significance for both.

The TPLF’s decades-long hostility with Eritrea means that political developments in Tigray cannot easily be separated from Ethiopian-Eritrean relations.

The 2020–2022 war temporarily aligned Addis Ababa and Asmara against the TPLF. After the war, however, Tigray became one of the places where their interests could diverge again.

By 2025, analysts were warning that tensions between Ethiopia and Eritrea were being driven by overlapping disputes involving Tigray and Ethiopia’s pursuit of Red Sea access. Chatham House described the relationship as increasingly dangerous and called for preventive diplomacy.

In 2026, the situation deteriorated much further.

The 2026 rupture

The latest breakdown is occurring in the context of renewed fighting in Tigray.

In September 2026, Tigrayan forces launched a major offensive, taking control of several airports and clashing with Ethiopian federal forces. The fighting rapidly expanded, raising concerns that the conflict could become regional.

The diplomatic relationship between Ethiopia and Eritrea deteriorated at the same time.

On October 1, Ethiopia ordered the closure of its embassy in Eritrea and declared 10 Eritrean diplomats persona non grata. Eritrea responded by severing diplomatic ties.

Ethiopia has accused Eritrea of supporting forces opposed to the federal government. Eritrea has denied such allegations.

The timing is significant. The two countries that cooperated militarily during the first Tigray war are now again on opposing sides of a regional strategic crisis.

By October 4, Ethiopian federal forces had retaken Mekelle from Tigrayan forces, although the TPLF described its withdrawal as tactical. Fighting continued elsewhere in northern Ethiopia.

Why the 2018 peace did not permanently settle the relationship

The central lesson of the past three decades is that peace agreements have repeatedly addressed the immediate conflict without eliminating the strategic conditions that make confrontation attractive or politically useful to both governments.

The 2000 Algiers Agreement stopped the border war but did not produce lasting reconciliation.

The 2018 peace declaration ended the state of war and reopened diplomatic relations, but it did not create a comprehensive framework for managing future disagreements over security, trade, borders and regional politics.

The 2020–2022 alliance demonstrated how quickly common interests could transform former enemies into military partners.

The post-2022 deterioration demonstrated the reverse: once the common enemy disappeared from the immediate strategic equation, the old disagreements became important again.

The deeper problem is bigger than the border

It is tempting to explain Ethiopia–Eritrea tensions as an unresolved border dispute. The border remains important, but that explanation is incomplete.

There are at least four overlapping strategic questions:

Territory: Where exactly is the border, and how should contested areas be administered?

Security: Can either government tolerate military or political activity by its adversary near its frontier?

Tigray: What political and military role will Tigrayan forces and institutions play inside Ethiopia, and how will that affect Eritrea’s security calculations?

The Red Sea: How can landlocked Ethiopia obtain reliable maritime access without creating an existential security concern for Eritrea?

These questions reinforce one another.

A disagreement over sea access can affect military planning. Military planning can affect relations with Tigrayan actors. Tigray’s political position can affect Eritrea’s security calculations. And unresolved territorial questions can make every military movement appear more threatening.

That interconnectedness is why individual diplomatic disputes can escalate so quickly.

What could prevent another Ethiopia–Eritrea war?

The immediate priority is preventing the Tigray conflict from becoming a direct interstate confrontation.

That requires more than statements calling for restraint. Ethiopia and Eritrea would need mechanisms for communication, border de-escalation and verification that reduce the risk of military incidents being interpreted as deliberate attacks.

The African Union has repeatedly called for restraint as tensions have risen. In September 2026, it warned that renewed fighting in northern Ethiopia threatened the gains of the peace process.

A durable settlement would also need to address the issues that repeatedly sit underneath the crises rather than treating each flare-up as an isolated event.

For Ethiopia, that means finding a sustainable formula for maritime access that does not depend on coercion or create intolerable security fears in neighboring coastal states.

For Eritrea, it means finding a way to address its security concerns without allowing the relationship with Ethiopia to become permanently defined by military confrontation.

For both countries, it means creating diplomatic and economic relationships that can survive changes in leadership and temporary shifts in regional alliances.

The unresolved question is whether the cycle can finally be broken

The history of Ethiopia and Eritrea shows that reconciliation is possible—but also that reconciliation between governments is not necessarily the same as resolving the strategic relationship.

The 2018 peace demonstrated how quickly hostility could give way to cooperation. The Tigray war demonstrated how powerful a shared adversary could be in sustaining that cooperation. The breakdown that followed demonstrates the limits of an alliance built primarily around a common enemy.

The most consequential question now is whether Ethiopia and Eritrea can negotiate the two issues that have repeatedly outlasted individual peace deals: Ethiopia’s search for secure access to the Red Sea and Eritrea’s determination to preserve its territorial and national security. If those interests remain mutually threatening, another agreement may stop the next crisis without preventing the one after it. If they can be placed inside a durable regional framework—with Tigray’s political future, border security and maritime access addressed together—the countries have a much better chance of ending the cycle in which war produces peace, peace produces a temporary alliance, and the alliance eventually gives way to another confrontation.