Good crisis management must constantly re-examine its assumptions. During the Obama administration, I coordinated the Agency for International Development’s West African operations to end the 2014 Ebola outbreak. We constantly thought about potential weaknesses in our strategy. The White House’s “Ebola czar,” Ron Klain, was notorious for pressing agencies to review potential weaknesses in strategy, demonstrate that they were thinking around corners and test underlying presumptions. My team once spent a weekend gaming out what would happen if commercial air travel to West Africa was shut down. We did not expect this to happen, but if it had it would have torpedoed our entire strategy by keeping us from moving Ebola responders in and out of the region.

The Trump administration failed to apply another lesson of the Ebola fight: Overseas containment and domestic readiness go hand in hand. The two cases of Ebola transmission in Dallas in October 2014 revealed that hospitals were not always ready to manage new infectious threats. After those incidents, the Obama administration began investing in health systems readiness and created a new team on the National Security Council to coordinate readiness for outbreaks abroad and at home. Yet, in an astonishingly shortsighted move, John Bolton dissolved that directorate upon his arrival as national security adviser. The White House followed this up by allowing post-Ebola investments in American and global outbreak readiness to lapse after their Obama-era funds began expiring.

We’re seeing the results of these cascading mistakes. In California, 124 health care staff members went into self-quarantine, unable to do their jobs, after exposure to a single person who had gone untested because of C.D.C. guidelines. A transmission cluster in a Kirkland, Wash., nursing home exposed numerous staff members and residents and forced a quarter of the town’s firefighters into isolation. Nurses in California have bemoaned the lack of support and advance planning, which has put them at risk. Twitter has been full of complaints about people with Covid-19-like symptoms unable to access testing.

What’s most infuriating is that these risks were widely predicted by experts outside government. To give but one example, two people who had served in the Trump administration — the former Food and Drug Administration commissioner Scott Gottlieb and a former National Security Council official, Luciana Borio — wrote in The Wall Street Journal on Jan. 28 that the United States should immediately scale up testing and get the hospital system ready.

The strategic miscues, the surveillance failures and the lack of attention to domestic readiness all flow from the same source: a White House strategy driven more by a political narrative than public health expertise.

Many officials have a hand in this mess, but the president is the crucial variable. Errors happen in any crisis. But when a president insists on claiming success irrespective of reality, it becomes much harder for those under him to acknowledge and correct mistakes. When he shows more interest in calming markets than in protecting Americans, he makes it very hard for senior public health officials to take aggressive action. (Mr. Trump reportedly became furious after a senior C.D.C. official’s prescient comments on looming risks sent markets tumbling.)

As Dr. Anthony Fauci of the National Institutes of Health told Politico in an interview last week, there is always a strong pull “to tell the president what you think he wants to hear,” even as officials have to “walk the fine balance of making sure you continue to tell the truth.” These things should not be mutually exclusive in a public health emergency.