Within the slow-brewing crisis of antibiotic resistance—which according to the Centers for Disease Control and Prevention kills 23,000 Americans each year—there are a lot of failures: of health care personnel who prescribe drugs when they should not; of patients who take drugs badly and encourage resistance to develop; of the drugs themselves, which no longer work against bacteria with toughened defenses. But an important and little-discussed part of the problem is that, once resistance undermines the action of some antibiotics, there are few other drugs to resort to.

If you accept that the antibiotic era began with the first uses of penicillin in 1943, then we had about 65 years of easy access to a pipeline of antibiotics that delivered reliable new cures when resistance made older drugs