Countable: a person (or group) who supports war.
The prowars in the cabinet pushed for immediate intervention.
Милитаристы в кабинете министров настаивали на немедленном вмешательстве.
Used attributively to describe a stance that supports war; not normally gradable.
The candidate's prowar rhetoric alienated many voters.
Милитаристская риторика кандидата оттолкнула многих избирателей.