Early last month, US House Republicans rammed through the American Health Care Act, a remarkably regressive piece of legislation that, among other flaws, would be disastrous for pandemic planning and preparedness. The bill eliminates funding for the Prevention and Public Health Fund, which was created under the 2010 Affordable Care Act to invest in vaccination programs, electronic laboratory reporting of infectious diseases, and infection-prevention programs. Vaccines are an important preventive strategy against deadly pandemics, while electronic lab reporting facilitates a rapid response to disease. In other words, these are precisely the funds that will be needed to prevent the next Ebola or Zika virus from turning into a national catastrophe.

In late May, the Congressional Budget Office delivered its projections on the House bill’s costs and impacts, finding that it would leave an estimated 51 million people under the age of 65 uninsured by 2026—23 million more than the estimated 28 million who will be uninsured under the current law. A Senate version of the bill may not pass, which would end Congressional Republicans’ umpteenth attempt to undermine or reverse the Affordable Care Act. But we can be sure their fight will continue, and that has important national security implications even beyond slashing emergency-planning funds (which, by the way, Trump’s proposed federal budget also does).

Cutting the Prevention and Public Health Fund, which deals directly with planning for bioterror attacks and pandemics, was only the most obvious way in which the House bill attempted to undermine American security. Over the long term, there is also a movement afoot to put basic health care out of reach of many Americans. Simply making healthcare unaffordable may seem less dramatic than slashing an emergency-preparedness budget, but doing so also undermines national security.

As the Congressional Budget Office report suggests, the American Health Care Act would make healthcare essentially unaffordable for people with pre-existing conditions, because it would allow insurance companies to dramatically increase their premiums. Ten years ago, I wrote about the security impact of the uninsured during the George W. Bush presidency. In 2005, almost 47 million people (about 16 percent of the total US population) were uninsured. Thanks to the Affordable Care Act passed under the Obama administration, that number dropped to a low of 11 percent, according to a Gallup poll taken during the first quarter of 2016. The Affordable Care Act was a big step in the right direction, but it didn’t close the gap, and the national security and public health challenges of having a large fraction of the population uninsured remain as relevant today as they were a decade ago.

Uninsured people delay seeking health care. Once they seek it, often in a busy emergency room, they are typically given less attention than people with insurance. This failure to get care becomes a danger not only for the individual but for the public at large when the problem is a deadly infectious disease. We saw this scenario play out in Dallas during the Ebola crisis of 2014 and 2015. A poor Liberian man, infected with the virus, presented himself to Texas Health Presbyterian Hospital with severe abdominal pain and a high fever. He was examined and sent home with a bottle of antibiotics. Amazingly, he did not set off an Ebola outbreak in his community, though the risk that he could have was significant and the wider public shouldn’t count on being so lucky next time. Before dying, he infected two nurses who had received inadequate training and equipment to protect themselves.

During the anthrax crisis of 2001, in which spores of the deadly disease were sent through the US mail, many people infected were federal employees with health insurance. If these postal workers hadn’t had easy access to health care, the death toll might have been higher than only five; 17 more were infected but survived thanks to timely medical attention. Anthrax spores do not spread from person to person, but it’s no stretch to imagine a different scenario: Suppose a future attack involves smallpox, a highly communicable virus, and that the initial victims are uninsured childcare workers or food handlers. The initial signs of smallpox include fever, chills, and headache. Uninsured victims would likely delay trying to get care, hoping for the symptoms to pass. By waiting they would certainly expose others to the virus, potentially setting of a pandemic.

Countries like Canada, which has universal health coverage and a well-funded public health infrastructure, are much better prepared to handle deadly epidemics. In 2003, Canada confronted Severe Acute Respiratory Syndrome (SARS), which originated in China. A physician from Guangdong province inadvertently infected a number of tourists with the SARS virus, setting off a global pandemic after everyone returned to their home countries. Among the infected travelers was an elderly Canadian woman who returned to Toronto after a 10-day vacation in Hong Kong.

Over the course of about four months, the Canadian health system worked hard to contain the virus, treating 400 people who became ill and quarantining 25,000 Toronto residents who may have been exposed. Ultimately, 44 people died from the disease in Canada, but the result would have been much worse without a quick and well-organized response.

The Canadian government’s response had its glitches—primarily in the form of poor political leadership. Mel Lastman, the mayor of Toronto and a former furniture salesman, became angry when the World Health Organization (WHO) issued a travel advisory against his city. He railed against the WHO’s decision on television, revealing his complete lack of knowledge about either the organization or public health in general. As a result of Lastman’s poor leadership, he was ultimately relegated to a secondary role as the deputy mayor took his place. Lastman’s credibility and legitimacy never recovered from the SARS outbreak. Likewise, US leaders will be judged by how they handle a bioterrorist attack or pandemic.

Unlike Canada, America’s piecemeal healthcare and public health systems are inherently less able to handle such crises. The Affordable Care Act helped fill in the gaps, but really, the only way to prepare for the eventuality of pandemics or bioterrorist attacks is with a single-payer government-run system that covers everyone. The United States might consider modeling its health care system after the one in Israel, a country that, given longstanding threats, takes every terrorist risk very seriously. In 1994, it established universal health coverage for all citizens. The country’s Ministry of Health monitors and promotes public health, oversees the operations of the nation’s hospitals, and sets healthcare priorities. As a result, Israel’s public health, emergency response, and hospital systems are state-of-the-art, highly efficient, and coordinated—a necessity when responding to terrorist attacks.

The preamble to the US Constitution states the goals to “provide for the common defense” and “promote the general Welfare.” The US government won’t fulfill either of these duties if it fails to protect its citizens against pandemics and bioterrorism. The mandate requires a robust public health infrastructure and a universal healthcare system that covers all Americans. The Trump Administration and Congressional Republicans threaten to undermine this essential function of government, unnecessarily jeopardizing American lives.