Russian culture is pretty much the embodiment of might makes right. If you inflict harm on someone weaker than you to prove a point, you’re manly. If you had the opportunity to inflict harm on someone and get away with it, but chose not to, you’re a coward. The military recruitment and hazing process only servers to turn this up to 11.
This has been the basis of Russia for the last 3 centuries if not longer, and its how they think the world should work, but can’t figure out why everyone hates them, especially those both geographically and culturally close to them.