The most urgent and dangerous threat to U.S. national security is not North Korea, foreign terrorists or any of the other seemingly menacing global dangers dominating the news. Today, the greatest threat to national security is President Donald Trump's assault on the rule of law and the U.S. Constitution.

Trump's response to the attack in Charlottesville, Virginia and his pardon of former Maricopa County, Arizona Sheriff Joe Arpaio make clear that the president is using the most powerful position in the country to undermine the rule of law and therefore the very safety of the people he has sworn to protect. By endorsing law enforcement's abuse of power, while also giving domestic terrorists the go-ahead to spark violence, Trump is lighting fuses on opposite sides of a powder keg.

The success of American democracy comes from a pervasive belief in the rule of law and that all are equal before it. But the rule of law is fragile and dependent on faith. Once people lose faith in it, the door to anarchy opens.

Trump is targeting America's faith in the rule of law. He obstructed justice in the investigation into his ties to Russian interference in the 2016 campaign. He criticized judges that have ruled against his proposed immigration policies. And he attacked the credibility of a judge presiding over a case involving Trump University.

But Trump's most recent actions go beyond undermining the principle of the rule of law – they actively promote its violent disruption.

Trump's endorsement of the abuse of power by law enforcement is a frontal assault on the rule of law. At a gathering of police officers in July, Trump explicitly endorsed police brutality. The United States already has a serious problem with excessive use of force by the police, and Trump's encouragement could make it much worse. Trump's decision this week to allow for the transfer of military-grade equipment, like armored vehicles, to local police forces seems to fit with his view of the need for the heavy hand of "law and order."

Last week, Trump further doubled-down by pardoning Arpaio, who was found guilty of criminal contempt for disobeying a judge's order to stop racial profiling, and who repeatedly disregarded the basic rights of his inmates. In doing so, Trump was effectively preventing a federal court from upholding our nation's most fundamental laws. This pardon signals that the president supports those who further his goals by breaking the law.

This is where Trump's stoking violence by hate groups becomes even scarier. After a neo-Nazi in Charlottesville killed one person and injured 19 by driving a car through a crowd, Trump insisted that there was violence "on many sides." While Trump immediately and unequivocally condemned attacks in Europe by terrorists driving cars through crowds, Trump excused a neo-Nazi that used the same tactic in a domestic terrorist attack. This was an endorsement (and not Trump's first) of right-wing hate groups, and was interpreted as such by neo-Nazis. It should come as no surprise that Trump has cut funding for Department of Homeland Security programs targeting white supremacists and neo-Nazis.

Look closely at the events of Charlottesville and Trump's response, and one can see just how tenuous the rule of law is in America. Neo-Nazis and white supremacists marched in the streets of Charlottesville, and self-proclaimed militia openly brandished guns while dressed in military fatigues as if they were headed into combat. Afterwards, videos emerged of beatings and shots fired at crowds.

Through it all, Trump uses the language of law and order as a cover for his authoritarian actions. He is pulling directly from the dictator's playbook, perfected over millennia by ruthless leaders in order to maintain power. One witness to the Charlottesville attack pointed out that the scene resembled that of war-torn countries where leaders used identity-based divisions to further their power, resulting in mass violence. The danger is that as tensions mount and hate-driven violence increases, the law-and-order message becomes more potent, and the abuse of power by the state expands.

It may be difficult for Americans to believe that their own president is actively working to undermine not just values and norms, but the very security that most Americans take for granted. Intentional or not, Trump's actions are both condoning violence from his supporters and assaulting the system that protects those who disagree with him.

The stakes are as high as they get. As former Vice President Joe Biden noted, "We are living through a battle for the soul of our nation. The giant forward steps we have taken in recent years on civil liberties and human rights are being met by a ferocious pushback from the oldest and darkest forces in America." This threat to the basic peace and stability of the country is a national security challenge of the highest order.