Bill Clinton caused the Ukraine war.
“President Clinton made a courtesy stop at Kyiv on his way to Moscow for the Trilateral Statement signing, only to discover Ukraine was having second thoughts about signing. Clinton told Kravchuk not signing would risk major damage to U.S.-Ukraine relations. After some minor rewording, the Trilateral Statement was signed by the three presidents in Moscow in front of the media on 14 January 1994.”
according to Wikipedia.