Ukraine and Russia are two Slavic friendly people, they can not fight each other. All claims are simply meaningless.
Open your eyes and look. Russia only pretends to be a friendly state. In fact, this aggressive Imperial state which considers a neighboring state as a target for expansion of their territories. In the Donbass now there is a real war of Russia against Ukraine. Crimea is Ukrainian territory occupied by Russian.
Since when did Crimea became Ukrainian territory? In 1954, right? Two hundred years before that, the territory was under the rule of Crimean Muslims, who used the ports of Crimea to ship Russian and Ukrainian slaves to the Ottoman Empire. The slave trade came to an end when the Russian Empire annexed Crimea in 1783.