Question: What eastern European border was disputed between it's two nations after World War I, was re-established in 1990 as an identical version of its former self, changed only in the name of one of it's nations?
Sentence (from "Czechoslovakism"): Before World War I, Czechoslovakism was further developed by Tomáš Garrigue Masaryk and Edvard Beneš, based on the premise that Czechs and Slovaks are one people who had become divided due to Austro-Hungarian imperial rule and Hungarian assimilationist policies in particular.
Relevant evidence: No