It started when Sovietball was collapsing and Chechnyaball had the confidence of declaring indepedence. When Chechnyaball did, Russiaball didn't liked hearing this and sent troops to stop him. But because of Russiaball's military strength being extremely reduced and not having the same as Sovietball's, he couldn't beat Chechnyaball. Russiaball was forced to call quits and have Chechnyaball have his indepedence. This war is considered an extreme embarrassment to Russiaball even to this day.
But it doesn't end there since there is a sequel.