Ukraine has an interesting history and it's capitol Kiev was once the capital of Russia prior to 1240 AD when the Mongols invaded and the Kevin Russ moved to the area around what is now Moscow. Then Poland rulled from the 13th century through the 16th century. In 1596 the Ukrainian Orthodox church asked the Czar of Moscovy for protection from Poland and he took over Keiv and it became part of the Russian Empire.
After the 1918 revolution Ukraine declared independence and the fight was on with the Red Army victory Ukraine became one of the founding republics of the USSR. With the break up of the USSR Ukraine again became independent but is once again in a struggle with its eastern neighbor. There is a tension between western [Polish] descendants and eastern [Russian] descendants of Ukraine.
It seems clear that the new Czar of Moscow is trying to reclaim what was once the land of the Russ.