With "involved" and without

I wonder if involved be removed from the definition below, would the definition still remains the same in meaning?

I feel there is a nuance. The definition is as crystal clear as is. Removing involved leads to a nuance, which I cannot tell.

Thanks in advance

Context:
mediator
Pronunciation: /ˈmiːdɪeɪtə/
NOUN
A person who attempts to make people involved in a conflict come to an agreement; a go-between: