IPA: /ˌɪntəˈvɛnʃənɪst/
KK: /ˌɪntərˈvɛnʃənɪst/
A person who supports or advocates for the practice of intervening, especially in political or social matters.
The interventionist argued that government action was necessary to address the crisis.
Interventionist → It is formed from "inter-" (meaning between) and "venire" (meaning to come). The word describes someone who comes in between to intervene in a situation.
Think of someone who 'comes in between' ('inter-') to help or change a situation — that's what an interventionist does.