THERE IS, alas, no shortage of ways to measure the damage done by the nationwide opioid epidemic, but perhaps the most dramatic is to consider how it has reversed four decades of progress against preventable deaths in the United States.

Between 1975 and 2015, hard work by government, the private sector and individuals cut the motor vehicle accident death rate by nearly half, from 20.6 per 100,000 people to 10.9. A similar all-out effort cut the homicide rate from 9.6 per 100,000 to 4.9. These figures translate into hundreds of thousands of lives saved. Yet the opioid epidemic has driven the national death rate from overdoses of these drugs to 9.3 per 100,000 in 2015, up from 0.4 in 1975, according to data assembled in a stunning new report from the congressional Joint Economic Committee’s Social Capital Project.

In other words, what was once a rare form of death has become an everyday event in America, supplanting previous forms of human tragedy and tearing families and communities apart just as murder and automotive crashes do.

How to reverse this catastrophe, and on much shorter than a four-decade timetable, is an urgent question. President Trump’s newly appointed Commission on Combating Drug Addiction and the Opioid Crisis, led by Gov. Chris Christie of New Jersey (R), issued its preliminary report Monday — and the recommendations were generally worthy. Treatment availability must be expanded “rapidly.” Prescribers must be thoroughly trained to recognize the risks of addiction and overdose associated with pain medications. Federal funds should support greater coordination among state prescription-drug-monitoring programs. And law enforcement should be enabled to interdict supply from overseas, focused especially on the flow of deadly fentanyl from China.

The commission’s headline recommendation was for Mr. Trump to declare a national emergency under one of two federal statutes, which would provide temporary (but renewable) authority for certain agencies to take otherwise impermissible but potentially helpful measures. Example: expanded federal support for inpatient drug treatment, most of which must be paid for by states under current law.

Well and good — though we would note that it should be possible to act as if there’s a national emergency without actually declaring one. Specifically, the president and both houses of Congress have spent the bulk of 2017 so far debating how much to cut Medicaid, which happens to pay for about a quarter of all addiction treatment. The House version of Obamacare repeal-and-replace legislation also could have watered down the requirement to include addiction treatment as an essential health-care benefit for private plans sold on the exchanges. Cutting health care amid an opioid epidemic makes no sense, as the commission’s lone Democratic governor, North Carolina’s Roy Cooper, pointed out. Perhaps in its final report, the commission will find a way to send that message to Mr. Trump — on an emergency basis.