Trump, as president, could launch a nuclear strike. This should scare you.

The president of the United States has the sole authority and power to launch the nation’s nuclear weapons. Think about that for a moment.

Donald Trump’s emotional, erratic, and unhinged behavior during his first term poses a grave threat to our national security. He has driven uncertainty to an aspect of the presidency that requires predictability: the global nuclear balance. This alone renders Trump dangerously unfit to serve as commander in chief.

For many Americans, Trump’s confusing rhetoric is all dismissed as political theater, performed to entertain rather than inform, with no consequences for Americans’ daily lives.

We are expected to laugh when Trump has been caught on tape on multiple occasions insulting veterans, POWs, Americans with disabilities, and active-duty troops who were wounded in battle. He has mocked heroes like the late Sen. John McCain, who was tortured after being shot down over Vietnam.

But today’s Trump is not the same man he was, even just since he left office in 2021. He is more and more detached from reality. In recent months, Trump has spoken publicly about the “late, great Hannibal Lecter,” and told a bizarre story about asking a ship manufacturer whether it was better to be electrocuted by a battery or eaten by a shark.

Even more concerning, he freely describes vengeance and dictatorship as the keys to his second term.

» READ MORE: The Trump Threat

If voters elect Trump in November, the entertainment value of his bombastic nonsense will immediately fade. His frequent gibberish and observable mental decline would disqualify him if he were Lt. Trump, charged with the most minor of duties maintaining America’s nuclear arsenal. The fact that he could once again have the power to unilaterally initiate a nuclear strike should put fear in all our hearts.

Unlike many other decisions in government, there exists no fail-safe mechanism to restrain a president’s potentially impulsive actions in this realm.

The process of managing our nuclear arsenal is designed for speed, to ensure the president has the capability to rapidly respond in minutes to an incoming strategic strike on the United States or one of its allies. There is no obligation to consult with the secretary of defense, the Joint Chiefs of Staff, or the director of national intelligence, none of whom hold any formal veto power over the president’s decision-making. That leaves the fate of millions hanging on the whims of a single individual.

This sobering reality becomes an immediate existential risk when combined with Trump’s mental instability, emotional insecurities, and his evident lack of any moral compass.

Former officials, regardless of political affiliation, have raised alarming concerns about Trump’s temperament and capability to handle the responsibilities of his office, particularly in matters of national security. The list of former national security officials who worked directly for Trump who are forcefully declining to support him is continuing to grow and includes former Chief of Staff Gen. John Kelly, former Secretaries of Defense James Mattis and Mark Esper, and former national security advisers H.R. McMaster and John Bolton.

It is telling, too, that these figures all point to the same liabilities: Trump’s propensity for petty grievances, emotional outbursts, and dismissal of the views of seasoned advisers, as well as ignoring protocols with alarming nonchalance.

The implications of such behavior become even more dire when juxtaposed with the indiscriminate power of nuclear weapons to destroy our very civilization. In a world where the margin for error is razor-thin, the consequences of a misguided or impulsive decision in this realm are simply unthinkable. The specter of a nuclear conflict, triggered by the capricious actions of a leader unfit for the responsibilities he bears, looms ominously over the global stage.

The margin for error is razor-thin.

Moreover, Trump’s erratic conduct undermines the delicate balance of deterrence that has upheld relative peace since the Cold War and has become even more fragile since Russia’s full-scale invasion of Ukraine in 2022. In that conflict, Russian President Vladimir Putin has repeatedly resorted to nuclear blackmail to intimidate the United States and its NATO allies from helping Ukraine defend itself. Thanks to President Joe Biden’s leadership, he has thus far failed to drive a wedge between NATO allies. What has Trump said about NATO unity? He has encouraged Russian leaders to do “whatever the hell they want” if U.S. allies don’t pay more for their defense.

In a challenging future environment, in which Russia and other adversaries scrutinize every move for signs of weakness or instability, Trump’s unpredictable behavior could erode the credibility of America’s nuclear deterrent. The erosion of trust in the United States’ commitment to responsible nuclear stewardship could unnerve our allies, embolden rival powers, and heighten risks of miscalculation and unintended escalation.

Ultimately, the nuclear peril of a second Trump presidency transcends partisan divides and ideological differences. It is a sobering reminder of the awesome responsibilities entrusted to the president as our nation’s commander in chief.

The stakes could not be higher. The complacency of decent Americans serves Trump’s advantage. We must prevent this outcome on Election Day.

Thomas Countryman served as acting under secretary of state and as assistant secretary of state for international security and nonproliferation under the administrations of Barack Obama and Donald Trump. Alexander Vershbow served as deputy secretary general of NATO, assistant secretary of defense for international security, and ambassador to NATO, Russia, and the Republic of Korea under the administrations of Bill Clinton, George W. Bush, and Obama. He is now a resident of Philadelphia and a senior adviser at the University of Pennsylvania’s Perry World House.