In order to determine if the continued presence of the EDF in Ethiopia amounts to an IAC ¹between Eritrea and Ethiopia, and possibly a situation of belligerent occupation, it is essential to assess whether Ethiopia has consented to this presence and to what extent. 

As stated by the ICRC in its commentaries, “[a]ny unconsented-to military operations by one State in the territory of another State should be interpreted as an armed interference in the latter’s sphere of sovereignty and thus may be an international armed conflict under Article 2(1)”. ICRC, 2016 Commentary, § 237. Such consent “must have been previously expressed or established (explicitly or tacitly). It must be valid, i.e. given by an authority authorized to do so on behalf of the State, and given without any coercion from the intervening State. […] [h]owever, the existence of such consent might be very difficult to establish for a number of reasons. States often do not publicize their consensual agreements. Moreover, the intervention of a third State might not give rise to any protest from the territorial State […] the absence of protest is a strong indicator of the existence of – at least – tacit consent […].” ICRC, 2016 Commentary, § 263. See also: ILC, Draft articles on Responsibility of   for Internationally Wrongful Acts, with commentaries, 2001, p. 73, §§ 3 and 8. Moreover, any prior consent could be withdrawn at any time, without further formality, including by protesting against the presence of foreign troops initially authorized. ICJ, Armed Activities on the Territory of the Congo (Democratic Republic of the Congo v. Uganda), Judgment, I.C.J. Reports 2005, p. 168, §§ 47 and 53.

Although Ethiopia has never officially requested or authorized Eritrean military involvement in Tigray conflict nor the continued presence of EDF, E. Bekel and U. Steinwehr, ‘Are other nations involved in the war in Tigray?’, DW, 19 March 2021. the intervention of the EDF is generally described as having been accepted, or even requested, by Ethiopia. ‘Ethiopia’s Tigray conflict escalates as leader claims Eritrea is participating in a ‘full-scale war’, ABC, 15 November 2020; V. Čáslavová, ‘The Tigray Conflict and the Role of Eritrea’, HORN International Institute for Strategic Studies, 31 October 2022; T. Bekit and F. Chothia, ‘Eritreans hunted down as military call-up intensifies over Ethiopia’s Tigray war’, BBC, 12 October 2022; J. Clifford, ‘Turn the R2P Around: Eritrea’s Intervention in Ethiopia’, Columbia Journal of Transnational Law, 1 November 2022; G. Kurtz, S. Roll and T. von Lossow, ‘Escalations Risks in the Horn of Africa’, SWP Comment no. 50, German Institute for International and Security Affairs, October 2024, p. 5; ‘The Enemy of my Enemy is my Friend: Ethiopia – Eritrea Relations and the 2020 Conflict in the Tigray Region in Ethiopia’, ACCORD, 4 March 2025. Following reports of serious abuses and multiple statements calling for the EDF withdrawal, Ethiopia announced in early April 2021 that the EDF would leave Tigray. ‘Eritrean forces should leave Ethiopia’s Tigray immediately: US’, Al Jazeera, 27 January 2021; ‘Ethiopia says Eritrean soldiers have begun withdrawal from Tigray’, France 24, 4 April 2021. See also above ‘Major events and developments’. Moreover, the Pretoria Agreement stipulates that Ethiopia must safeguard its territory against foreign incursion. Agreement for lasting peace through a permanent cessation of hostilities between the government of the Federal democratic Republic of Ethiopia and the Tigray People’s Liberation Front (TPLF), Article 8. However, the federal government of Ethiopia has never protested against the EDF presence on its territory. On the contrary, sole the Tigray Interim Administration denounced the presence of the EDF and requested their withdrawal. K. Abate, ‘At AU summit, Tigray demands full implementation of peace deal’, VOA, 17 February 2025; N. Yoseph, ‘Calls for restraint sound out as tensions threaten to erupt in Tigray’, The Reporter Ethiopia, 15 March 2025. The absence of an official statement or agreement concerning the EDF’s presence therefore appears to be the result of a deliberate political decision rather than a genuine lack of consent. This is evidenced by Ethiopia’s lack of objection to Eritrea’s military involvement, including after the end of Tigray conflict.

Consequently, based on circumstantial evidence, even though tensions between Ethiopia and Eritrea have been recently reported, as long as there is no use of armed force between both countries and no protest by Ethiopia against Eritrea’s presence, it cannot be conclusively determined that Eritrea is occupying Ethiopia or that there is an IAC between the two countries.

• 1
  between Eritrea and Ethiopia