Q:  a person died defending muslim people and he was a nonmuslim (atheist). Can a nonmuslim be shaheed? IAm told if Allah Wills he can make him a shaheed. (text)
A: In Islam, a muslim can only be a shaheed.

A nonmuslim helping and defending muslims is an honorable feature. We too should assist in defending the rights of believers and nonbelievers. His/her reward would be in this world insha-allah. The title of shaheed in the context of the question would be only apply towards a muslim.

Allah Certainly Knows Best.