Czechs in Ukraine Mostly, they were women with ethnic Ukrainian husbands. Some others stayed of their own choice. During the Soviet era, they were one of the most affected groups by the Chernobyl nuclear power plant disaster in 1986. At the end of the 1980s, ten thousand Czechs lived in Ukraine. At the beginning of the 90s Czechoslovakia invited these remaining Czechs to return to the Czech Republic, which in 1993 almost 2,000 people did, and other people came to the Czech Republic in later years. As of today, Volhynian Czechs are still migrating. In 2014, after the revolution in Ukraine and the
Nuclear weapons and Ukraine of Independent States. In 1994 Ukraine agreed to destroy the weapons, and to join the Treaty on the Non-Proliferation of Nuclear Weapons (NPT). As a republic in the Soviet Union, Ukraine was the base for the following nuclear forces: International relations theorist John Mearsheimer predicted a Ukraine without any nuclear deterrent was likely to be subjected to aggression by Russia, but this was very much a minority view at the time. A 2016 study argues that the denuclearization of Ukraine was not a "stupid mistake" and that it is unclear that Ukraine would be better off as a nuclear state.