In early November 2020, the Ethiopian federal government launched a military operation against the TPLF-controlled authorities in the Tigray region. But the decision to turn political tensions into an open war has had profound regional implications too. In a complex and interconnected regional system, spillovers from the Tigray crisis will likely threaten the fragile balance of power – one that was still to fully reap the benefits of the Ethiopia-Eritrea peace deal of 2018 – and weaken future prospects for stability in the Greater Horn of Africa. Will Ethiopia make it through the conflict with the TPLF without further fuelling secessionist dynamics? How will Ethiopia relations with its neighbouring countries be affected by the crisis? And what role could non-African actors and multilateral institutions play in the evolving scenario?