Dissolution of Czechoslovakia
Since the federalization in 1968, Czechoslovakia had divided citizenship, either of the Czech Socialist Republic or of the Slovak Socialist Republic (the word 'Socialist' was dropped from both names shortly after the Velvet Revolution). This distinction, however, had little effect on the citizen's life. On January 1, 1993, all Czechoslovak citizens automatically became citizens either of the Czech Republic or the Slovak Republic, based on their previous citizenship, permanent residence address, birthplace, family ties, job, and other criteria. Additionally, people had one year's time to claim the other citizenship under certain conditions.
Czechoslovakia–Poland relations
Czechoslovakia gained independence in the aftermath of World War I, as Austria-Hungary fell apart, just as Poland regained independence as the Second Polish Republic after 123 years of partitions. Both emerging countries shared a long border, and soon became enveloped in a border conflict. Although it never developed into an open war, this conflict led to uneasy relations between both states in the interwar period.