How do their goverments being democratic have anything to do with their potential for invasion? Please go back in time and tell half of Europe this argument dur

How do their goverments being democratic have anything to do with their potential for invasion? Please go back in time and tell half of Europe this argument during WW2. This has nothing to do with the stability of their govt or society. It has a to do with their belligerent neighbors (and their own belligerent policies).