The west also assumes it has the right to invade or attack other nations, for example Iraq, Afghanistan and Libya. They also wanted to attack Syria but luckily thanks to President Putin that never happened. To grab Ukraine the west carried out a coup in Ukraine, Russia is simply responding to this and supporting those who do not back that coup. I would imagine if we go back and look carefully one will find that the uprisings in Libya and Syria were also western created events just to create the false need for military attacks by the west.
The minor difference being although the west went into other countries, they went into stabilise the Country and leave, Russia has no agenda to depart.