There is a moment in any deteriorating relationship when the language used to describe it changes. The words that once conveyed manageable tension — "mistrust," "rivalry," "unresolved grievances" — give way to a different vocabulary. Analysts covering the Ethiopia–Eritrea relationship have now reached that threshold. The terms appearing in serious assessments of the situation along Ethiopia's northern border include "powder keg," "regional mega-war," and "Africa's second world war."
These are not the words of alarmists. They are the words of regional specialists who have watched, with mounting concern, a set of overlapping developments that individually might be managed but together constitute something more volatile than any single element suggests.
The 2018 peace between Abiy Ahmed and Isaias Afwerki was celebrated as one of the Horn's most significant breakthroughs in decades. It ended a twenty-year frozen conflict, won Abiy the Nobel Peace Prize, and briefly suggested that the region's most intractable bilateral hostility had found a resolution. What it did not do — as became apparent during the Tigray War, when Eritrean forces fought alongside Ethiopia's federal army — was build the institutional foundations of a durable peace. It was a personal compact between two leaders, not a settled relationship between two states. Personal compacts have a way of unravelling when the interests behind them diverge.
The interests have now diverged.
The Flip That Changes Everything
To understand why the Ethiopia–Eritrea situation has escalated from cold tension to war-scare territory, the critical development is the apparent shift in the relationship between Eritrea and the TPLF.
The Tigray People's Liberation Front and Eritrea were, for thirty years, bitter enemies. The 1998–2000 Eritrea-Ethiopia border war — which killed an estimated 80,000 people — was fought largely between Eritrean forces and a federal army dominated by the TPLF. Isaias Afwerki spent two decades nursing a visceral hatred of the TPLF leadership that was personal as well as political. When Abiy Ahmed launched the Tigray military offensive in November 2020, Eritrea's decision to join — sending troops deep into Tigray — reflected, among other things, the opportunity to settle accounts with an old enemy.
The suggestion now — and it is still more suggestion than confirmed fact, based on the patterns analysts are observing — is that Eritrea and elements of the TPLF may be finding a shared interest against Addis Ababa. Former enemies united by a common present adversary is one of the oldest stories in regional politics. But when those former enemies are Eritrea and the TPLF, the implications for Ethiopia's stability are severe.
In 2020, Eritrea's military involvement tipped the balance of the Tigray War decisively against the TPLF in its early phases. If Eritrea has now repositioned toward TPLF-aligned interests — even partially, even tactically — then Ethiopia's northern border faces a threat environment fundamentally different from anything Abiy's government has planned for. The Pretoria Agreement's transitional arrangements were designed for a post-war settlement between Ethiopia and the TPLF, not for a scenario in which Eritrea is a hostile variable rather than a tacit partner.
What Isaias Wants
Understanding Eritrea's repositioning requires understanding what Isaias Afwerki has always wanted and how the regional situation has evolved relative to those goals.
Isaias has never been a reliable partner for anyone, including Ethiopia. He joined the Tigray war because it served his interests at that moment — the destruction of TPLF power, the demonstration of Eritrean military relevance, and the consolidation of his relationship with a new Ethiopian leader whose dependence on Asmara's support gave Isaias leverage. What Eritrea received in return was less clear. The border demarcation promised under the 2018 peace agreement was never implemented. Eritrea's economy remained isolated. The international rehabilitation Isaias may have hoped for — a softening of sanctions, a return to diplomatic normalcy — did not materialise.
An Isaias who feels he gave more than he received from the 2018 compact, who watches Ethiopia strengthening ties with the UAE and Somaliland, who sees his country's strategic value being gradually bypassed as Assab remains underutilised and Berbera emerges as the preferred alternative — that Isaias has incentives to make himself relevant again through disruption rather than cooperation. Regional instability has historically been a more effective tool for Asmara's leverage than regional stability.
Tigray's Internal Fracture
The TPLF's internal fragmentation adds a further layer of instability that the Pretoria Agreement was not designed to handle. The Pretoria framework assumed a TPLF capable of delivering on its commitments — disarming fighters, accepting federal oversight of Tigray's administration, cooperating with the transitional governance arrangements. What has emerged instead is a TPLF whose internal divisions have produced competing factions with different relationships to the peace process.
Reports of the TPLF restoring old regional structures, reasserting administrative authority in ways that challenge Pretoria's arrangements, and conducting political activity that resembles the escalation pattern preceding the 2020 war have alarmed observers who remember how quickly that situation moved from political tension to open conflict. The question being asked by regional analysts — whether Pretoria is collapsing slowly, whether Ethiopia is losing effective control over the post-war arrangements in Tigray — is not a marginal concern. It is the central question about whether the Tigray War's settlement will hold.
The Pretoria Agreement's fragility was always understood by those who negotiated it. It was an agreement that stopped the fighting without resolving the underlying political questions about Tigray's relationship to the federal government, the accountability for atrocities, and the long-term status of Tigray's administration. Those unresolved questions are now being tested by a TPLF that does not speak with a single voice and an Eritrea that may have concluded its interests are no longer served by Ethiopian stability.
The Troop Movement Question
Reports of increased troop movements along Ethiopia's northern border are difficult to independently verify, but they are consistent with a pattern of military repositioning that both sides would undertake if they assessed the risk of conflict as rising. Ethiopia has every incentive to reinforce positions along a border it cannot afford to have tested while simultaneously managing the Oromia insurgency in the south and unresolved tensions in Amhara. Eritrea has every incentive to make its military presence felt along a border whose formal demarcation has never been implemented.
Ethiopia's accusation that Eritrea is maintaining forces inside Ethiopian territory — occupation and interference being the framing used in Addis Ababa — reflects a relationship that has moved well beyond the diplomatic friction of cold tension into something that carries the formal vocabulary of territorial dispute. These are the kinds of accusations that, in this region's history, have preceded war.
The Scenario That Should Alarm Everyone
The worst-case scenario being privately discussed in diplomatic circles is not a direct Ethiopia–Eritrea interstate war, though that cannot be ruled out. It is a scenario in which Eritrean support — material, logistical, or political — for TPLF factions opposed to the Pretoria framework tips Tigray back into active conflict while Ethiopia is simultaneously managing the Oromia insurgency, facing economic stress from inflation and foreign exchange shortages, and navigating the intensifying proxy contest involving Egypt, Somalia, and Sudan.
A multi-front Ethiopia, under pressure from north and south simultaneously, with Sudan's war continuing to destabilise the western border and the Red Sea corridor becoming an active theatre of great-power competition — that is the regional mega-war scenario that analysts are trying to prevent by naming it clearly enough that the actors involved understand what they are risking.
The 2018 peace was real, in the sense that it stopped a war and opened a border. But a peace built on personal chemistry between two leaders, without institutional foundations, without border demarcation, and without the kind of economic interdependence that gives both sides a concrete stake in the other's stability — that peace was always provisional. The provisionality is now visible.
Whether this ends in renewed conflict or a managed return to cold tension will depend on decisions being made in Asmara, Addis Ababa, Mekelle, and the capitals of the powers with influence over the region's trajectory. What it will not depend on is the 2018 Nobel Peace Prize, which described a moment that has now definitively passed.