These figures in this series assume that much of the economy reopens by early summer and there's a quick recovery. They do not account for future stimulus that may attempt to jump start the economy, or on-going support for workers and businesses who struggle under slow, uneven re-openings. There also could be aid to state and local governments and to provide additional broad economic assistance.

In 1918, months of national lock-downs was unthinkable. That's in part because the US government did not have the fiscal space to shut down the economy and provide so much economic support. Thus, with a long, uncertain future ahead and these unsustainable costs continuing to rise, it is vitally important for lawmakers and governors to find a safe way to reopen the economy, and—once the economy recovers—to begin to address the stratospheric rise in government debt.

Brian Riedl is a senior fellow at the Manhattan Institute. He is the author of the new report, "Coronavirus Budget Projections: Escalating Deficits and Debt." Follow him on Twitter @Brian_Riedl.