What should the president do if Congress refuses to raise the debt limit? The question is like asking what the president should do if Congress orders him to drop a nuclear bomb on Manhattan. He should act in the public interest and accept the consequences. The legalistic argle-bargle necessary to take him from A to B is almost beside the point. But perhaps it is a worthwhile exercise to imagine what the law would say.

Imagine, then, that Congress does not raise the debt limit. Sometime later this month, it becomes impossible for the Treasury to pay all U.S. obligations—including interest on the national debt, payments to Social Security and Medicare recipients, and salaries and pensions to government employees such as soldiers and food inspectors. Tax and other revenues coming in will fall short of payments that must go out. If the president does not violate the debt limit and borrow more, he will have to choose among these obligations, paying some and defaulting on others.

It is hard to imagine such a state of affairs lasting very long (or even getting started), but imagine we must. If the president stops paying interest on the debt, financial markets could freeze up, as they did in 2008. Banks would shut down, people would be thrown out of work. If the president instead stops making Social Security and Medicare payments, or stops paying the salaries of soldiers, a huge amount of hardship and even danger would result. Whatever he chooses, the United States would be thrown into its most dangerous crisis since the Depression. By contrast, if he borrows money above the debt limit, then he can continue to make payments and avoid these bad outcomes.

So it is more likely that the president will borrow money in violation of the debt limit (assuming as we must that he and Congress do not compromise) than that he cuts spending. He could conceivably make three legal arguments that he possesses the power to do so.

First, he could argue that, under the best reading of the relevant statutes, Congress has in fact ordered him to borrow rather than cut expenditures.Appropriations statutes order him to spend and do not give him the authority to cut spending. If revenues fall short, he normally can borrow, but the debt limit will prevent him from doing that, and other laws forbid him to raise funds in other ways, for example, by raising taxes or selling federal property. So there seems to be an inconsistency among the statutes. When statutes are inconsistent, they must be reconciled in the best way possible. And there is a rule that a later statute—here the appropriations laws—supersede earlier statutes, the debt ceiling. But that interpretation implies that the debt ceiling is meaningless, and that Congress could not erect a debt ceiling even if it wanted to. Conflicting statutes should be reconciled so as to preserve their meaning as much as possible. A better interpretation, which preserves a meaning for both the debt ceiling statute and the appropriations statutes, is that the commands to spend are implicitly conditional on sufficient funds being available. As the money dwindles, the president must cut expenditures commensurately.