Political map of Russia & the former Soviet Union 18 June 1995 (First Chechen War): The end of the Soviet Union sparked secessionist movements across the former Soviet republics. In late 1994 Yeltsin (Boris Yeltsin)’s Russian government invaded the breakaway republic of Chechnya in an attempt to restore Russian federal control there (First Chechen War). Although the Russians initially proved successful, continued Chechen resistance and poor federal morale pushed Yeltsin to agree to a ceasefire in 1996.