Answer: Militarism is the belief or desire of a government or people that a country should maintain a strong military capability and be prepared to use it aggressively to defend or promote national interests.
Nationalism: identification with one’s own nation and support for its interests, especially to the conclusion of the interests of other nations.
Both have major roles in war
Nationalism is the belief that people’s greatest loyalty should be to their nation.
Militarism kinda implies the glorification of the military of their country.