In times of national crisis, people look to the president for direction, reassurance and confidence. President Trump’s Oval Office speech on Wednesday night provided precisely the opposite.

From the misstatements to the omissions to his labored demeanor, the president sent a message that shook financial markets, disrupted relations with European allies, confused his many viewers and undermined the most precious commodity of any president, his credibility.

With the stock markets plunging into bear territory, the health-care system struggling to keep pace with the spreading novel coronavirus and Americans wondering what’s next, Trump is dealing unsteadily with the greatest crisis of his presidency. The pandemic is a physical and economic threat to the well-being of millions of Americans. It also has become a political threat to the president’s hopes for a second term.

Historians will eventually assess the president’s prime-time effort to calm a scared and nervous nation that is taking unprecedented steps to deal with the coronavirus pandemic. In the moment and in the immediate aftermath of the speech, the judgments were as harsh as at any time in Trump’s presidency.

Almost everything that could have gone wrong with the speech did go wrong. Stock futures began to crater as the president was speaking. Government officials were forced to correct the mistakes Trump made in describing the travel ban he was imposing. Anyone looking for information about the health-care system’s capacity to respond was left wanting.

Trump said that “we have been in frequent contact with our allies” about the crisis, but European leaders were caught off guard by the new travel restrictions and issued a harsh statement in response.

“The European Union disapproves of the fact that the U.S. decision to impose a travel ban was taken unilaterally and without consultation,” said the statement signed by two leaders of the E.U.

This has been described as akin to President George W. Bush’s “Katrina moment,” the botched response to the 2005 hurricane that flooded parts of New Orleans. But for all the devastation caused by that storm, the coronavirus is far worse in its impacts and disruptions, and the consequences for Trump are potentially enormous. Daily life has been upended across the country in ways unimaginable when the virus began to hit people. The president’s tweets, meanwhile, swing from upbeat claims to dire warnings to medical advice.

This is a crisis not of the president’s making, but Trump has become the government’s least credible leader in the response to it. He is a cheerleader by nature, a president who is more comfortable dealing in exaggerations than facts. Trained scientists and medical doctors in government have sought to provide realistic assessments to the public. Trump has made false predictions and statements that contradict the experts.

Visiting the Centers for Disease Control and Prevention last Friday, he said tests for the virus were available to anyone who wanted one, a demonstrably false statement at a time when the government was rushing to get more tests out and available, as other officials were acknowledging.

Trump went on to say those tests were totally reliable and, in a statement that revealed his own state of mind, drew a comparison with his telephone call to the Ukrainian president that led to his impeachment and acquittal. “The tests are all perfect, like the letter was perfect,” he said. “The transcription was perfect.”

Vice President Pence, who is in charge of the overall federal response to the pandemic, has tried to project a sense of calm and knowledgeability. He defers as is necessary to the experts in the government. But he also feels a need constantly to praise the president, as if Trump has truly been the stable, guiding hand in all this.

Immediately after Trump spoke Wednesday night, the White House and an official at the Department of Homeland Security clarified misleading or incorrect statements made during the speech. Asked about this on Thursday morning on CNN, Pence replied, “I don’t think there was confusion,” and he went on to praise the president for more “historic” steps.

Pence and those on the team tasked with coordinating the response are working cooperatively with state and local leaders, which is critical at this moment. Meanwhile, the president has called Gov. Jay Inslee (D) of Washington, where the outbreak has brought more deaths than anywhere in the country, “a snake.”

The president looks to blame others. It’s correct that the Chinese government made all this worse by initially trying to cover up the outbreak, which contributed to the virus’s rapid spreading there and now around the world. But trying to make this into some kind of foreign invasion belies the nature of the pandemic.

Trump blames Federal Reserve Chair Jerome H. Powell for the tanking stock markets. The Washington Post reported Wednesday that an angry president ordered Treasury Secretary Steven Mnuchin to press Powell to take more-aggressive action to stimulate the economy. Never mind that the Fed’s first attempt to do so recently did nothing to prevent the markets from falling further.

The president spoke Wednesday night about forthcoming economic proposals designed to aid companies and individuals as they cope with the financial burdens of the crisis. Some things he can do by executive action; others, such as his call for payroll tax relief, would require congressional action and coordination with congressional Democrats. On Wednesday, House Democrats outlined their own package of economic assistance.

There is no more important priority for the president now than dealing with the coronavirus. By his tweets, it is evident he finds regular distractions, including the contest for the Democratic presidential nomination. He has chosen to be a frequent commentator about the Democratic race, a kibitzer and a disrupter.

He has suggested that the Democratic establishment has robbed Sen. Bernie Sanders (I-Vt.) of the nomination. He has claimed that Sen. Elizabeth Warren (D-Mass.) has helped weaken Sanders and thereby strengthened Joe Biden.

His Ukraine intervention was designed to harm Biden, and now it is all but certain that Biden will be his opponent in the general election. But before he gets to that confrontation, he must deal with the threats posed to the country by the deadly coronavirus.

“This is just a temporary moment of time that we will overcome together as a nation and as a world,” Trump said from the Oval Office on Wednesday night.

That is everyone’s hope. And along with that hope is a desire for the president to provide the leadership the moment demands.