Slovakia
The Slovak Republic and the Czech Republic went their separate ways after 1 January 1993, an event sometimes called the Velvet Divorce. Slovakia has remained a close partner with the Czech Republic. Both countries co-operate with Hungary and Poland in the Visegrád Group. Slovakia became a member of NATO on 29 March 2004 and of the European Union on 1 May 2004. On 1 January 2009, Slovakia adopted the Euro as its national currency.
Zaolzie
Poland signed a treaty with Czechoslovakia in Warsaw on 13 June 1958 confirming the border as it existed on 1 January 1938. After the Communist takeover of power, the industrial boom continued and many immigrants arrived in the area (mostly from other parts of Czechoslovakia, mainly from Slovakia). The arrival of Slovaks significantly changed the ethnic structure of the area, as almost all the Slovak immigrants assimilated into the Czech majority in the course of time. The number of self-declared Slovaks is rapidly declining. The last Slovak elementary school was closed in Karviná several years ago. Since the dissolution of Czechoslovakia in 1993, Zaolzie has been part of the independent Czech Republic. However a significant Polish minority still remains there.