Walk crisis
The Walk Crisis (also called the Valga Crisis or the Valka Crisis, after the Estonian and Latvian names of the town, respectively) was an episode in Estonia–Latvia relations over the territorial dispute along the border between the two countries, chiefly about the town of Walk (now Valga, Estonia and Valka, Latvia) and the island of Runö (now Ruhnu, Estonia). The territorial dispute lasted from 1918 when both countries declared independence, until its settlement in a border treaty in October 1920.