Second, develop domestic manufacturing capacity. It is imperative that the United States identify critical resources that must be manufactured, along with their component parts, domestically. Key pharmaceuticals and other health care equipment are an obvious place to start. These are strategic necessities akin to the Department of Defense ensuring that essential military gear is made here. Mr. Trump took the right first step by invoking the Defense Production Act. Now he must use it. Longer term, the federal government must pass “buy American” legislation for a wide range of products. Using preferences won’t do; everyone knows how to get around them. The federal government must also be prepared to be the buyer of last resort that keeps manufacturing of important products with low profit margins viable in the United States. We must treat antibiotics, vaccines, masks and other medical items as though they are vital to our national security, because they are.

Third, there must be a science and technology initiative directed at developing new means of identifying pathogens and other public health risks, testing for them, containing them, treating them and, ideally, curing them. Increasing the capacity of our health care system to handle pandemics is essential. It will save lives and reduce the need for the widespread shutdowns and quarantines we’re now experiencing and will thus prevent the accompanying economic destruction that on its own will cause much suffering. Focused efforts that lead to new scientific discoveries could not only prevent or dramatically limit future outbreaks but could also create a virtuous cycle of discovery and development that makes the country more secure and more prosperous.

If Mr. Trump does these things, he will see the nation through a major crisis, put his naysayers to shame and create a lasting institutional legacy that will make the nation more secure in the future. What’s more, it would enable the United States to help friends in need. For all the claims that Mr. Trump’s America First foreign policy degraded America’s leading position in the world, his critics seem to have forgotten that exporting our manufacturing base to China also meant abandoning America’s ability to lead in many situations like this one. America wasn’t the country shipping crucial supplies to Italy because we couldn’t. We don’t even have enough to meet our own needs. That is a far more dangerous surrender of American leadership than is wanting to reduce America’s involvement in military conflicts abroad.

The world looks to America for leadership, but that leadership comes with responsibilities. We could send plenty of management consultants and bankers to hard-hit Bergamo, but it wouldn’t help. There are plenty in New York, and it’s not helping there either. Sending ventilators and masks and pharmaceuticals would help, but we don’t have that ability.

If the president prepares a plan to build the domestic capacity to quickly and effectively address future public health threats, Americans will be more secure, the world can have confidence in American leadership in times of crisis and Mr. Trump will have earned the support of American voters in November. This will require the president to buck some conventional Republican sentiment about the proper use of government power. But the true spirit of conservatism recognizes that there is no more legitimate use of that power than to protect American lives. Now is his chance to do just that.

Christopher Buskirk (@thechrisbuskirk) is the editor and publisher of the journal American Greatness and a contributing opinion writer.