In just a few lines, the poem takes a sharp look at the super-rich who dream of leaving Earth. The speaker calls them "kings" who "play Indian on Mars," a phrase that suggests dress-up, as if colonizing another planet were a game of pretending to be pioneers or settlers. The word "play" makes their ambitions sound childish, even though the stakes are enormous.
Meanwhile, the "world on fire" keeps insisting that "trade is great." The contrast is bleak: the planet burns while the powerful carry on with business as usual and look for an exit.
The last stanza turns coldly dark. "Better that they believe / they shall not return" can be read as a wish that these men leave and stay gone. The tone is sardonic and weary, with anger held under tight control. The short, plain lines make the judgment feel quiet but final, like a dry remark made while watching something absurd unfold.