Spender Poem

Hey there,

I'm writing an analysis of Spenders Ultima Ratio Regum poem for a term paper, and even though it is quite easy to understand I have trouble interpreting some of the lines. The first two line's are: The gun spells money's ultimate reason/ in letters of lead on the spring hillside. What would you say Spender means by writing that?

And also, in the last lines of the poem he writes O world, O death...why would he write the last words in some kind of untypical pathos?

Can someone help me? Thank you.