What is the theme in At the Bomb Testing Site by William Stafford?

Death is a central theme in this book. "At the Bomb Testing Site" makes a big point by focusing on something very small: a solitary desert lizard facing destruction. By describing something concrete, the poem addresses the unimaginable. It works by subtly enlarging our perceptions of nature, violence, and death. The poem is written in a quiet, casual tone that increases in intensity in the third stanza but never mentions the words "death" or "war." Instead we get that information from the title and infer the rest from the unfolding description of the lizard. The closest the poem comes to a direct comment is in line 11 's "a change," which is a euphemism for "annihilation." In this context, the word "change" is chilling - how can we think of death this way? If we follow this reasoning, we must wonder how we can read the casualties of a bombing as just numbers on a page, or how a soldier can turn a key that will end up killing thousands.