Refers to an ideology or policy that emphasizes military power and the use of force, often in political contexts.
That country's militarism was criticized by the international community.
軍国主義 is a more common term for militarism, often associated with pre-WWII Japan. 武断主義 is less frequent and may carry a nuance of rule by military force rather than a broader ideology.
Compound of 武断 (military decision/force) and 主義 (principle/ism). The exact historical derivation is uncertain; it is a Sino-Japanese term likely coined in the modern era to translate Western concepts of militarism.