The Russia and Ukraine situation

You have probably heard in the news about the war going on between Russia and Ukraine but it’s never really answered why this war even started in the first place, I personally do not know the exact reason but I would like to present some theories on the matter. Theory number one, if you have looked back into any Russian history you may know that Russia was governed by the now defect Soviet Union and under the Soviet Union, Russia had control over several countries like Estonia, Azerbaijan, and Ukraine. The Soviet Union fell on December 26th, 1991, and many countries had either already broke away from Russian rule or claimed independence after, although those countries broke away it seems like Russia wants them back and is starting with Ukraine but the real question is will they take over and who is next? A second theory I have in mind is that do you know Ukraine is on top of one of the largest deposits of Uranium in the world, the deposit can be found in the Novokonstantinovskoye Mine. A quick science lesson for you is that Uranium is radioactive and is used to power nuclear engines used in such things as nuclear power plants or reactors in submarines meaning they can be used to fuel war weapons but Uranium is mostly used for Nuclear bombs. The whole Uranium deposit is important because if Russia takes the power over Ukraine it gets the mineral rights to all of that Uranium. Though these might be just theories at the end of the day this is what I believed either started or contributed to the ongoing war but I’m curious to hear what your thoughts are and if you have a theory on the matter