In a new Commentary article about U.S. Rep. Paul Ryan‘s battle to rein in federal government spending, James Pethokoukis of the American Enterprise Institute offers the following sobering data about entitlement spending:

Washington budgeteers like to joke that the U.S. government is really just a giant insurance company with an army. Not true, at least not yet. But the day is coming. And when it does, even the Army might need to get cut from the equation. Last year, Washington spending amounted to 24.1 percent of GDP — the second highest level since World War II and its immediate aftermath.

Separating out interest payments on the $11 trillion national debt leaves 22.6 percent of GDP spent on what most Americans consider federal programs. And of that amount, nearly half (10.4 percent) was spent on the three safety-net entitlements: Social Security (4.8 percent), Medicare (3.7 percent), and Medicaid (1.9 percent). By 2035, the Congressional Budget Office says, 16.5 percent will be spent on those social insurance programs. Add back 8.9 percent for interest payments, and you will have already spent 25.4 percent of GDP without yet ponying up a nickel for whatever else Americans think worthy of taxpayer funds over those 23 years: not only the military and infrastructure and the like, but nuclear-fusion pilot projects, space-traffic controllers for orbital tourist cruisers, brigades of drone marines. (Oh, and sugar subsidies.) Beyond that, Medicare in particular will continue to gobble up a larger and larger share of the pie. And this all assumes that a debt crisis doesn’t bring the economy down by then.