Ethiopia–Eritrea border war (1998–2000)
A border dispute over the town of Badme escalated into full-scale war between Ethiopia and Eritrea. Tens of thousands of soldiers died in trench warfare before a peace agreement was signed in Algiers in 2000.
A UN boundary commission was set up, but Ethiopia refused to accept its ruling on Badme.
The two countries stayed in a frozen conflict until a 2018 peace deal reopened ties.
Shows how a border incident combined with accusations of proxy support can pull two exhausted armies into direct war.
