Poles tried to retrieve the lands which once, before the last partition in 1795, had formally made an integral part of the Polish Lithuanian Commonwealth.
So, we can consider, that Crimea, that till 1954 (if memory serves me correctly) was an integral part of RSFSR, and was handed to Ukrainian SSR by Kruschev without any referendum and with violation of constitutional procedure, can be considered rightfully Russian.
We should add that population there is preliminarily Russian, language used everywhere is Russian (that was acted to banderists as red maleta to corrida bulls). In addition, there was referendum in 1991 (as Crimea was autonomous republic within Ukrainian SSR, it had right to choose their way if republic leave Union - became part of Union, became independent, or be part of same republic). You can look what outcome that referendum had in wikipedia, for example. But ukrainian nationalistic government simply ignored results if referendum. (BTW: Georgian nazis also "played" similar way with similar referendum in Southern Ossetia at same time, and there was low intensity armed conflict till 2008).
People of Crimea returned to this question in 2014, with known results.
About the body bags - I strongly suspect that if the Russian Marines landed in Odessa, the worst danger they would face is being strangled in the arms of the locals and drowning in reproaches for not coming sooner. The Bandera abomination will already be halfway to the Polish border at that point.