The Ethiopia-Eritrea border conflict serves as a stark reminder of how colonial-era decisions, made with little regard for local realities, continue to shape the political and economic landscapes of modern states. This is particularly evident in the case of Assab, a strategic port city on the Red Sea. The contested status of Assab has left Ethiopia, Africa’s second-most populous nation, landlocked. The legacy of ambiguous colonial demarcations, coupled with Eritrea’s unilateral claim to Assab after its independence, has not only fueled tensions but also hindered Ethiopia’s access to maritime trade, creating both economic and geopolitical vulnerabilities that persist to this day.

The roots of the Ethiopia-Eritrea border dispute lie in the colonial treaties signed between Italy and Ethiopia in the late 19th and early 20th centuries. These agreements, including the treaties of 1900, 1902, and 1908, aimed to define the boundary between the Italian-controlled territory of Eritrea and Ethiopia. However, the treaties were fraught with ambiguities, relying on vague geographic markers like rivers, without conducting precise ground surveys. This lack of specificity created room for differing interpretations of where the border truly lay. Italy’s colonial ambitions complicated matters further. After declaring Eritrea an Italian colony in 1890, Italy sought to extend its control over Ethiopian territories by exploiting these ambiguities. This ultimately led to Italy’s invasion of Ethiopia in 1935 and the establishment of Italian East Africa, which merged Eritrea, Ethiopia, and Somalia into a single colonial entity. During this period, boundaries were arbitrarily redrawn to serve colonial administrative needs, rather than reflecting the historical or ethnic realities of the region.

The situation worsened after World War II, when Britain temporarily took control of Eritrea following Italy’s defeat. The British, too, redrew borders without consulting the local populations or Ethiopian authorities. These arbitrary border changes left a legacy of contested claims that resurfaced when Eritrea gained independence in 1993.

Assab’s status is particularly contentious because of its strategic importance as a port city on the Red Sea. Historically, Assab was treated as distinct from Eritrea proper. During Ethiopia’s federation with Eritrea from 1952 to 1962, Assab was governed as an autonomous region rather than an integral part of Eritrea. This distinction was reinforced by Ethiopia’s Proclamation No. 16/1980, which designated Assab as a separate administrative entity, alongside Tigray, Dire Dawa, and Ogaden. When Eritrea seceded in 1993 following a referendum facilitated by the Ethiopian People’s Revolutionary Democratic Front (EPRDF), it unilaterally claimed Assab, without international arbitration or Ethiopian consent. This move violated established principles of state succession under international law, which generally respect pre-existing administrative boundaries during independence transitions. Assab, unlike other parts of Eritrea, had historically been administered separately and was primarily inhabited by Afar communities who shared stronger cultural and economic ties with Ethiopia’s Afar population than with Eritrean highlanders.

Eritrea’s claim to Assab relied on flawed colonial treaties that had long been invalidated. For example, Italy’s invasion of Ethiopia in 1935 constituted a material breach that nullified any prior agreements between the two nations. Additionally, post-World War II agreements, such as the 1947 peace treaty signed by Italy, explicitly terminated Italy’s colonial claims over African territories, including those involving Ethiopian borders. Beyond the political implications, the loss of Assab has deeply strained Ethiopia-Eritrea relations and destabilized the broader Horn of Africa region. Ethnic communities, especially the Afar, have faced displacement and marginalization due to the unresolved border disputes.

Ethiopia’s loss of Assab left the country landlocked, severely hindering its economic development. Before Eritrea’s independence, Assab served as Ethiopia’s main port, handling two-thirds of its maritime trade. Losing access to this vital port forced Ethiopia to rely on Djibouti for its imports and exports, significantly increasing costs. This dependence on Djibouti has made Ethiopia vulnerable to external pressures and regional instability, as any disruption in Djibouti’s port operations could cripple Ethiopian trade. Furthermore, Ethiopia’s exclusion from the Red Sea has limited its influence in one of the world’s most critical maritime corridors. The Red Sea connects Europe to Asia via the Suez Canal, serving as a vital route for global trade and energy shipments. By losing direct access to this crucial corridor, Ethiopia has been sidelined in regional geopolitics, while Eritrea retains control over key ports such as Assab and Massawa.

The unresolved ambiguities surrounding Assab’s status have perpetuated tensions between Ethiopia and Eritrea for decades. The Algiers Agreement, which sought to resolve these disputes following the Eritrean-Ethiopian War of 1998-2000, failed to address the core issues at play. The Eritrea-Ethiopia Boundary Commission (EEBC) based its decisions on colonial-era agreements without considering their invalidation due to Italy’s breaches or the subsequent geopolitical changes in the region. Moreover, the EEBC ignored the historical administrative distinctions between Assab and the rest of Eritrea, as well as the ethnic makeup of disputed areas like Assab, where Afar communities have consistently expressed grievances about being governed by Asmara.

The Algiers Agreement also failed to provide a mechanism for Ethiopia to regain sea access or to negotiate the equitable use of ports such as Assab. This omission has left Ethiopia economically disadvantaged and further entrenched the conflict. The case of Assab highlights how colonial-era ambiguities continue to fuel modern conflicts. For Ethiopia, reclaiming access to the Red Sea is not only a matter of historical justice but also an economic necessity. International law offers avenues to challenge Eritrea’s claim to Assab, based on principles of state succession, the invalidation of colonial treaties, and the rights of ethnic communities to self-determination.

A lasting resolution will require revisiting flawed frameworks like the Algiers Agreement, with a focus on equity and mutual benefit. A comprehensive solution should address Ethiopia’s legitimate need for maritime access while ensuring stability for both nations. Only by confronting these historical injustices can lasting peace be achieved in the Horn of Africa.