THE WISE heads in Washington seem to have agreed that we are headed for a government shutdown. Some folks have concluded that this outcome isn’t so bad, because it will make clear to the American people who the bad guys really are, or because once those mischievous legislators get the troublemaking out of their system they will settle down and steer the country away from even worse outcomes down the road.

Count us out of any such sophisticated complacency. Yes, defaulting on the U.S. debt would be worse than shutting down the government. But both represent such recklessly, breathtakingly, wastefully irresponsible derelictions of leadership that the people who run this town ought to be ashamed of themselves if either comes to pass. Moreover, we are not reassured by the argument that a shutdown would make a default, which could come in mid-October, less likely. As the habits of normal compromise and negotiation become ever more frayed, further deterioration strikes us as at least an equally plausible alternative to the hoped-for wake-up call that shocks the capital back to common sense.

The story by now is familiar, at least to the many Washingtonians whose livelihoods may soon be affected. Congress, unable to agree on a budget for next year, is trying to pass a temporary spending bill to keep the lights on until Dec. 15, or maybe just until Nov. 15. Republican Speaker John Boehner of Ohio, caving to a few dozen backbenchers who would rather blow things up than govern, has insisted that any such bill contain Obamacare poison pills that neither the Senate nor President Obama will accept. The Senate may say no, for a second time, on Monday, at which point the House can endorse a clean spending bill or let the government go over the cliff.

This prospect may not trouble some of the freshmen conservatives with few government workers in their district and little respect for what government does, but we would hope Mr. Boehner would have compassion for the thousands of moderately paid breadwinners who would find themselves in very difficult circumstances. We would hope he would be troubled by how a shutdown would disrupt research at the National Institutes of Health and safety inspections at the Food and Drug Administration, and by the lasting damage inflicted abroad as the United States comes to be seen as an unreliable laughingstock rather than a bulwark of its alliances.

Ultimately, the grown-ups in the room will have to do their jobs, which in a democracy with divided government means compromising for the common good. That means Mr. Boehner, his counterpart in the Senate, Harry M. Reid (D-Nev.), minority leaders Sen. Mitch McConnell (R-Ky.) and Rep. Nancy Pelosi (D-Calif.) and the president. Both sides are inordinately concerned with making sure that, if catastrophe comes, the other side takes the political hit. In truth, none of their reputations stands to benefit.