Militaristic mien refers to a hostile and aggressive demeanor that is associated with military culture. If you are looking for synonyms for this phrase, you can use terms like authoritarian, belligerent, combative, domineering, overbearing, pugnacious and quarrelsome. Other synonyms include aggressive, forceful, hawkish, jingoistic, militant, and warlike. You can also use words like combative, confrontational, bellicose, and truculent to describe someone with a militaristic mien. These terms are often used to describe individuals who exhibit behaviors that are closely associated with aggression and hostility. By using these synonyms, you can effectively express the attitude and behavior of someone with a militaristic mien.