Across the wealthy world, nations are reckoning with a quiet arithmetic — fewer births, longer lives, and the growing strain between those who work and those who rest. Australia now confronts this reckoning directly, as policymakers acknowledge that the country's economic model, long buoyed by immigration and a young workforce, cannot hold its shape against the tide of demographic change. The choices ahead — who pays, who works longer, who is welcomed in — are not merely fiscal questions but reflections of what a society believes it owes to its young, its old, and those yet to arrive.