Combat Mission: Black Sea is a military simulation depicting a fictional 2017 conflict between NATO and Russia in Ukraine. Following the events in Crimea and Eastern Ukraine in 2014, the Kiev government and Russia continue to clash over the status of the contested regions. This culminates several years later in a dramatic announcement by Ukraine that they will be joining NATO and the EU. Tensions explode as Russia perceives a direct threat to Russian citizens and deploy troops to the Ukrainian border again, while Western governments, welcoming a chance to expand NATO and EU influence eastward, mobilize as well. The escalation continues until the summer of 2017, when a large firefight erupts between Ukrainian and Russian troops in the Donetsk region. The next day fighting flares up on the border, and on a dark early morning in June 2017, pre-positioned Russian and NATO forces roll forward into Ukraine.
Source: The Developer Website.