I mean… It was a relic of immense power that was designed to keep both races safe.

Then one of the races stole it, murdered both guard and civilian alike while doing so, displaying total lack of care for the other races well being…

Wouldn’t you imagine that the marauding a-holes were probably going to use the relic to destroy the rest of your race too? In which case, yeah, you really fight tooth and flipper to get it back from them, ‘cose just dying out without a fight kinda sucks…