But if the administration announces a delay after insurers have committed to sell policies at prices that assumed a mandate (and functional exchanges), the administration may find it has thrown away the credibility it would need to persuade insurers to try again next year. Not to mention their credibility with young, healthy folks, who may simply assume that they can count on another delay.

Again, none of this is a 100 percent certainty. But the Affordable Care Act’s insurance market reforms have created a system prone to what Charles Perrow dubbed “Normal Accidents.” By “normal,” he didn’t mean “minor” — the lead exhibit was Three Mile Island. Rather, he meant something like “hard to avoid.” The system is both complex and tightly coupled: All the pieces are interdependent, so a failure in one part is apt to cascade throughout the market. This is not a system where you want to start pulling out one piece to see how well the rest can get along without it.

The administration clearly understood this — right up to the point where a major component failed. Now it’s apparently planning to keep the reactor running with as many pieces as possible in the hopes that none of it will unexpectedly blow up. This is not sound policy thinking, or even sound political thinking, and I think that all of us who care about keeping insurance available for ordinary Americans should try to talk them out of it — for their good, as well as our own.