Specifically, an exchange of gunfire at a watering hole near the border between Abyssinia and Italian Somaliland, during Dec 1934, between Italian officers with local troops who were illegally occupying the site and Ethiopian troops. Wal Wal was located about 60 miles inside the Ethiopian border. Mussolini set up and successfully used the situation to provoke the clash, demand unilateral reparations from Ethiopia which he knew they would not meet, and ultimately kick off a chain of events leading to the Italian invasion of Ethiopia and the effective destruction of the collective security mechanisms of the League of Nations (such as they were at the time).