The Slovakian War (known in Hungary as the Czechoslovak War) was an armed conflict fought prior to, during and after the independence struggles of various Eastern European nations in the late 1940s and 1950s. The war began as a territorial dispute between the Duchy of Hungary and the emerging Czechoslovak nationalist movement in the 1940s, which was exacerbated by the election of a sympathetic Social Democratic government in Austria in 1947 and eventually escalated into a full-on armed conflict between the Republic of Czechoslovakia and the Democratic Republic of Hungary, later Republic of Hungary over territorial control. With Hungary overwhelmed by other conflicts of the time and secret TATO support going to the Czechoslovaks, Czechoslovakia eventually won a decisive victory in the conflict and in the 1957 Slovakian Treaty the conflict was ended with a new border drawn in Czechoslovakia's favor.
The war was fought roughly simultaneously as the Transylvanian War between Hungary and Rumania, the Croatian War of Independence, and the Galician War between Poland and the Ukraine over control of the Republic of Galicia. As a result, it is regarded as one of the Austrian Wars and is lumped into the post-Austrian period of Eastern Europe.