However, disagreements about where the newly created international border should be caused relations to deteriorate significantly, eventually leading to full-scale war.

[35] The war officially came to an end with the signing of the Algiers Agreement on 12 December 2000;[36] however, the ensuing border conflict would continue on for nearly two decades.

Eritrea and Ethiopia both spent considerable amount of their revenue and wealth on the armament ahead of the war, and reportedly suffered between 70,000–300,000 deaths combined as a direct consequence thereof, excluding an indeterminate number of refugees.

After the war ended, the Eritrea–Ethiopia Boundary Commission, a body established by the Algiers Agreement, concluded that Badme, the disputed territory at the heart of the conflict, belongs to Eritrea.

Both conflicts lasted until 1991 when the Ethiopian People's Revolutionary Democratic Front (EPRDF) – a coalition of rebel groups led by the Tigray People's Liberation Front (TPLF) – overthrew the Derg government, and installed a transitional government in the Ethiopian capital Addis Ababa.

During the civil war, the groups fighting the Derg government had a common enemy, so the TPLF allied itself with the Eritrean People's Liberation Front (EPLF).

This referendum was held in April 1993, and the vote was overwhelmingly in favour of independence, leading to the establishment of a new state joining the United Nations.

[51][53][54] On 13 May 1998, Ethiopia, in what Eritrean radio described as a "total war" policy, mobilized its forces for a full assault against Eritrea.

On 5 June 1998, the Eritrean Air Force attacked an elementary school in Mekelle that killed 49 of the students and their parents and the neighbors that came to help immediately.

[58][59][60] The United Nations Security Council adopted Resolution 1177 condemning the use of force and welcomed statements from both sides to end the air strikes.

Eritrea refused, and instead demanded the demilitarization of all disputed areas along the common border, to be overseen by a neutral monitoring force, and direct talks.

[63][64] With Eritrea's refusal to accept the US/Rwanda peace plan, on 22 February 1999, Ethiopia launched a massive military offensive to recapture Badme.

[66] Ethiopia's offensive, codenamed Operation Sunset, began with an air attack on Assab airport by four Ethiopian fighter jets, followed by a massive artillery barrage against Eritrean positions on the Tsorona front, which was meant as a diversion to make the Eritreans prepare for an Ethiopian offensive against eastern or southern Eritrea.

Realizing that they were about to be cut off, the remaining Eritrean units deployed in the Badme area hastily retreated, abandoning nearly 100 kilometers of fortifications and most of their heavy weapons.

[61] According to some reports, trench warfare led to the loss of "thousands of young lives in human-wave assaults on Eritrea's positions".

[80] Also on 17 May, due to the continuing hostilities, the United Nations Security Council adopted Resolution 1298 imposing an arms embargo on both countries.

[81] By 23 May, Ethiopia claimed that its "troops had seized vital command posts in the heavily defended Zalambessa area, about 100 km (60 mi) south of the Eritrean capital, Asmara".

[75] But the Eritreans claimed they withdrew from the disputed border town of Zalambessa and other disputed areas on the central front as a "'goodwill' gesture to revive peace talks"[82] and claimed it was a 'tactical retreat' to take away one of Ethiopia's last remaining excuses for continuing the war;[83] a report from Chatham House observes, "the scale of Eritrean defeat was apparent when Eritrea unexpectedly accepted the OAU peace framework.

[17] Most international reports put the total war casualties from both sides as being around 70,000,[88] but some analysts within the region suggested that the overall death toll may have been as high as 300,000.

In July 1998, Ethiopia alleged that up to 60 Ethiopians had died in Assab after being locked in a shipping container by the Eritrean police in daytime temperatures of over 40C.

[96] According to Human Rights Watch, detainees on both sides were subject in some cases to torture, rape, or other degrading treatment.

The Eritrean government began supporting the Oromo Liberation Front,[92] a rebel group seeking independence of Oromia from Ethiopia that was based in a part of Somalia controlled by Mohamed Farrah Aidid.

On 14 April 2002, the Eritrea–Ethiopia Boundary Commission that was established under the Algiers Agreement in collaboration with Permanent Court of Arbitration in The Hague agreed upon a "final and binding" verdict.

For many people in both countries, Badme's fate became the primary indicator of whether the enormous loss of life during the fighting had been justified.