It took 38 minutes for officials to correct a false alert that said a missile was heading for Hawaii.Instagram/@sighpoutshrug/via REUTERS

The Cold War came to an end, somehow, without any of the world’s tens of thousands of nuclear warheads being fired. But there were decades-worth of close calls, high alerts, and simple mistakes that inched world leaders shockingly close to catastrophe.

Saturday’s terrifying, 38-minute episode in Hawaii will not go down as one of those close calls: Residents of the state waited for the bombs to fall after receiving text messages that a ballistic missile was on its way. FCC Chairman Ajit Pai on Sunday said “the government of Hawaii did not have reasonable safeguards or process controls in place to prevent the transmission of a false alert”—a case of human error, in other words.

But the episode did reveal the glaring deficiencies of an early-warning system that can easily misfire, along with some frightening truths about the speed at which policymakers and presidents must make decisions in the event that missiles really do fly. “Mistakes have happened and they will continue to happen,” the Arms Control Association’s Daryl Kimball told me. “But there is no fail safe against errors in judgment by human beings or the systems that provide early warning.”

As such, worries about miscalculation remain vivid. Vipin Narang, a political science professor at MIT focused on nuclear issues, tweeted one scenario on Saturday. “POTUS sees alert on his phone about an incoming toward Hawaii, pulls out the biscuit, turns to his military aide with the football and issues a valid and authentic order to launch nuclear weapons at North Korea. Think it can’t happen?”

The United States operates a series of radar and missile-defense systems across the Pacific. It includes satellites monitoring the Korean peninsula and fleets of American and Japanese warships equipped with the Aegis system, a powerful computing network that detects and tracks missile launches and aircraft. Those systems are tied to the U.S. Strategic Command’s Global Operations Center, buried deep underground in Nebraska, which monitors events around the world in real time and pumps that information to the Pentagon and the White House.

In the Hawaii incident, there was little danger of the United States firing off a nuclear response. Military officials knew within minutes of receiving the alert that there was no threat to U.S. territory; none of the Pentagon and U.S. spy satellites or the ground and sea-based radars detected any sign of missile launches from North Korea, government officials told me.

But with a president obsessed with cable news and Twitter, the erroneous alert could have easily triggered an angry or provocative tweet, which could have been interpreted by the North Koreans or Russians as an imminent threat. According to pool reports, Trump was briefed on the false alarm while at his private golf course in Florida. Hours later, he tweeted about Hillary Clinton’s “missing” emails and the performance of the stock market. He has yet to comment on the incident despite knowing within minutes that all was safe, even as horrified Hawaiians continued to expect the worst.

“There are fail safes built into the system, but there aren’t enough fail safes,” Kingston Reif, director of threat reduction policy at the Arms Control Association, said. “If the president wants to respond—and there’s very little time to respond—the president and only the president has the sole authority or authorize the use of nuclear weapons,” he added.

President Trump’s apparent attempts to dictate national policy via tweet and his bombastic rhetoric about North Korean leader Kim Jung Un have seemingly raised the odds of a coming conflict. In August, Trump tweeted that “military solutions are now fully in place, locked and loaded, should North Korea act unwisely.” His advisors consistently warn that time is running out to stop the North Korean nuclear and ballistic missile programs

While the United States has a series of sophisticated early warning systems, potential adversaries do not, making initial statements from American officials critical in tense situations. “We have to be concerned about our adversaries early warning systems and their interpretation of these signals and messages,” Kimball said.

Entering this complex array of political signaling, high-tech surveillance, and careless tweeting, is the Pentagon’s new Nuclear Posture Review, the first since 2010. Originally slated for release next month, a draft of the document leaked this past week shows the Trump administration is lowering the bar for what would trigger an American nuclear response. It includes an entire section about non-nuclear strategic attacks that could spur an American nuclear response: cyber warfare, massive blows to critical infrastructure, and certain catastrophic attacks on civilians.

That is a “major expansion over Clinton, Bush and Obama,” all of whom attempted to reduce the role of nuclear weapons, Jon Wolfsthal, a former Obama official who worked on nuclear issues, told me. The new strategy views nuclear weapons as “a swiss army knife that can be pulled out to solve a range is issues,” he added. Among several new weapons the document proposes are so-called “low-yield nukes,” which could be placed on existing Trident ballistic missiles launched from submarines, lowering the threshold for use by causing less fallout, limiting the impact zone, and causing fewer civilian casualties.

As one defense official involved in nuclear issues put it: “We are self-deterred because our nuclear weapons are too big, and would cause too much damage if used.” The new strategy paper, then, expands the types of scenarios under which the United States would choose the nuclear option, which in turn “could lead to a new round of testing of nuclear weapons,” the official said.

Another concern is the lack of nuclear expertise currently at the White House and at the Pentagon. Key positions in the Pentagon’s policy-making offices remain unfilled or are only now seeing officials take their desks after a year of vacancies.  At the National Security Council, for example, Andrea Hall is currently serving as both director for Weapons of Mass Destruction on the National Security Council, and director for WMD, Terrorism and Threat Reduction, which were separate roles under previous administrations.

The new nuclear strategy, Wolfsthal said, indicates that under the Trump administration “there’s no downside to threatening the use of nuclear weapons.” Simply making the threat more explicit, and more likely to be acted upon, is seen as enough of a deterrent to sway potential adversaries. What the North Korean and Russian leadership think of these threats is something Washington will discover over time.