The crucial question about raising the federal debt ceiling is: What happens if Congress doesn’t? That is, what happens if Congress defaults? When President Trump returns from his “working vacation” later this month, this promises to be one of the major issues he’ll face, because the treasury is expected to run out of cash in early or mid-October, according to projections by the Congressional Budget Office.

The current debt ceiling is $19.8 trillion, which covers Treasury borrowings from the public (individuals, large institutional investors such as pension funds and banks) and from other government agencies (such as the Social Security Trust Fund or the Highway Trust Fund). If the government hit the ceiling and couldn’t pay all its bills, then someone would get stiffed: bondholders, Social Security recipients, soldiers and sailors, government vendors — and, possibly, many more.

The harder question is: How would the world react?