Answer
See below.
Work Step by Step
The sentence in "if...then" form is: If a person is a pacifist, then he or she is not a warmonger.
The contrapositive of $p\rightarrow q$ is $\sim q\rightarrow \sim p$.
The converse of $p\rightarrow q$ is $q \rightarrow p$.
The inverse of $p\rightarrow q$ is $\sim p\rightarrow \sim q$.
Hence here the converse is: If a person is not a warmonger, then he or she is a pacifist. The inverse: If a person is not a pacifist, then he or she is a warmonger. The contrapositive: If a person is a warmonger, then he or she is not a pacifist.