As similar as any country who ever invaded any other country?!

There are some pretty substantial differences. Russia is on the strategic back foot here trying to figure out a way to stop NATO's advance. They've only turned to violence after long attempts at resolving the tension diplomatically and the US has been implacable. Putin's actually been pretty hesitant in his escalations so far; he's 70 and has a long history of trying to avoid war.

Hitler was more about wanting more land and resources for Germany, and he saw war as being a legitimate tool for achieving his aims that he deployed early and enthusiastically.