The International Crisis Group has warned that escalating tensions between the Ethiopian federal government, the Tigray region and neighboring Eritrea could plunge the Horn of Africa back into a bloody war in three years.

The group warned in a statement that a variety of factors could trigger the conflict, saying that while it is easy to start a war, it will be much harder to stop it.

“A new war between Ethiopia, Eritrea and the Tigray region would be unsustainable,” said Murita Mutiga, the group’s Africa program director. “The risk appears to have deterred all three parties for now, but more must be done to prevent it from recurring.”

The organization’s deputy director, Magnus Tyler, said that since the end of the Tigray war, relations between Ethiopia and Eritrea have deteriorated, largely due to Prime Minister Abiy Ahmed’s desire for a seaport.

Eritrea fears that this desire “could include invasion.”

The deputy director said that Addis Ababa would accuse the Ethiopian People’s Revolutionary Democratic Front of colluding with Eritrea.

The Crisis Group’s statement said that the recent conflict between the federal government and Tigray forces, which has included drone attacks, could escalate into a full-scale war, drawing Eritrea into the conflict.

The organization also warned that a new conflict in northern Ethiopia could, in addition to the conflict in Sudan, attract powerful external actors and destabilize the volatile Red Sea region.