Was Jan. 6 the end of an era – or start of a dangerous new one?

Hours after President Joe Biden’s heavily defended inauguration and call for national unity and civility, about 100 anti-fascist protesters, many hooded and clad in black, vandalized federal and corporate buildings in downtown Seattle, burning a large U.S. flag, smashing windows, and spraying graffiti with messages such as “kill ICE” and “abolish everything.” They also hurled abuse at the new president.

Meanwhile, 60 miles to the south, hundreds of right-wing, pro-Trump demonstrators – some of them armed – have staged protests this month outside the Washington State Capitol in Olympia. Angry about pandemic restrictions and an election they believe was stolen, they broke into the compound of the governor’s mansion on Jan. 6, and then returned five days later to the adjacent state capitol where they confronted hundreds of National Guard soldiers deployed there.

From Oregon to Texas and Michigan to Washington, D.C., stark scenes like this have proliferated nationwide over the past year, underscoring the growing radicalization of extremist groups on both ends of the American political spectrum. 

The Jan. 6 storming of the Capitol in Washington exposed this ugly intolerance in graphic form. “The genie is out of the bottle,” says Chris Loftis, spokesman for the Washington State Patrol. “That genie had hid its face, but … it is with us,” he says, “exposing to everyone how deep and dangerous our vulnerabilities are.”

Indeed, 20 years after foreign extremists crashed planes into the Pentagon and World Trade Center, killing thousands and unleashing a global war on terrorism, Americans are waking up to a new, post-9/11 era defined by the need to combat a more insidious and potentially damaging threat: the escalating spiral of homegrown radicalism in their own backyard. 

“The putsch attempt on January 6 was both the end of an era and the beginning of another one,” says Vasabjit Banerjee, a political scientist who studies contentious politics at Mississippi State University in Starkville and author of “Undoing the Revolution.”

But precisely what kind of end or beginning will this be?

To Americans who had grown weary of tumultuous politics over the past four years, Donald Trump’s departure from the White House comes with hopes that some stability will return in the nation’s capital and beyond.

Mr. Biden has made national healing and unifying the overt goal of his presidency. And new efforts to counter extremism are percolating, from vigilance at social media platforms to more robust steps by law enforcement and state legislators. 

Yet experts say solutions to radicalism require persistent effort – even though the vast majority of Americans aren’t prone to political violence.

Outside the gold-domed Georgia Capitol in Atlanta, where dozens of desert-fatigued military police stood guard against a potential attack by pro-Trump forces on Jan. 18, church leader Nina Polk voices a blend of concern and cautious hope.

This moment, she hopes, marks the beginning of an era where the country begins to wrestle in earnest with fundamental divides and pain that have been fueled by disinformation, online hatred, and tribal politics. In fact, she has led a flock from her congregation on a mission to ease tensions.

“A kingdom divided against itself can’t stand,” she says as she takes in the surreal scene of a state capitol barricaded against assault amid a transfer of presidential power in Washington. 

Recipe for insurgency?

Last month, a North Carolina man and self-described member of the Boogaloo Bois – one of the violent right-wing extremist groups involved in attacking the Capitol – pleaded guilty to conspiring with the foreign terrorist organization Hamas to blow up a courthouse in Minnesota. 

The man, Benjamin Ryan Teeter, belonged to a Boogaloo Bois subgroup called the “Boojahideen.” He and a co-defendant allegedly offered to work as mercenaries for Hamas and provide material support in plots to destroy U.S. government buildings and attack U.S. soldiers overseas. 

Such actions – along with increasingly brazen threats and attacks against public officials – signal how loosely connected groups of individuals appear to be advancing beyond “domestic terrorism” toward the earliest stage of an insurgency, experts say. (The word “boogaloo” in these circles refers to an impending second U.S. civil war.)

“This is not going away anytime soon,” predicts retired Col. Lawrence Wilkerson, a fellow at the Quincy Institute, who helped war-game the possibility of violent disruptions to the 2020 election with the Transition Integrity Project.

On Wednesday, the acting secretary of Homeland Security issued an alert on domestic terrorism risks in the weeks ahead, from “extremists with objections to the exercise of governmental authority and the presidential transition, as well as other perceived grievances fueled by false narratives.”

Rooted in white supremacy, right-wing extremist groups and militia are increasingly recruiting from within U.S. military and law enforcement ranks and also communicating with neo-Nazi and other like-minded groups overseas, Colonel Wilkerson says. And they are seeking followers from the ranks of millions of disappointed supporters of former President Trump. 

The ground for such recruiting has become more fertile due to a range of trends affecting America well before Mr. Trump launched his presidential campaign. These include feelings of economic and cultural dislocation in an era of rapid change, growing distrust of institutions, and the rise of social media and increasingly partisan news outlets. The result, alongside populism, has been a growing prospect of violence at the fringes.

The United States faces an “incipient insurgency,” says David Kilcullen, a counterinsurgency expert, retired military officer, and professor at Arizona State University. This stage involves disparate groups growing more organized, training, building public and external support, and waging more coordinated anti-government attacks.

“You may have several simultaneous proto-insurgencies all happening at the same time, sponsored by different groups, and it’s often impossible to determine which, if any of those, will progress to a more serious stage,” Mr. Kilcullen said in an interview this month on WBUR. 

Extremists’ growing presence

The problem risks expanding beyond domestic terrorism, which has surged in recent years, even as the nation focused most of its resources on international terrorism. Federal prosecutions classified as domestic terrorism hit a record high last year. “Domestic terrorism and the far-right aspect of terrorism is now the greater threat to the homeland,” says Javed Ali, a former senior director of counterterrorism at the National Security Council.

The Biden administration on Friday directed law enforcement, intelligence, and security agencies to conduct a policy review of this “serious and growing national security threat,” said White House spokeswoman Jen Psaki.

Nationwide protests for racial justice sparked last May by the police killing of George Floyd attracted a volatile mix of right- and left-wing extremist organizations, including anti-fascist and anarchist protesters conducting vandalism and arson. 

With a rapidly proliferating presence on social media and fueled by viral disinformation, the often-clashing extremist groups feed off one another and have raised their public profiles, organizing openly and holding community events, with some members running for political office.   

The Jan. 6 assault on the Capitol has highlighted the risk of insider threats posed by extremist groups. So far, nearly 1 in 5 of the more than 140 people charged over their actions at the Capitol appear to have a history of military service, NPR reported. Defense Secretary Lloyd Austin vowed at his confirmation hearing to take on extremism in the military.

Dozens of sworn police officers from departments around the country also attended the Jan. 6 rally. Some stormed the Capitol and are facing federal criminal charges, investigations and possible expulsion, or other discipline.

Until now, state and local law enforcement agencies have often welcomed self-described militias to help police protests.

“There’s an ideological affinity that’s developed between police and armed, white militias. But as the Capitol siege showed, that’s an unholy alliance,” says Timothy Zick, a constitutional law professor at William & Mary Law School, in Williamsburg, Virginia. In short, “it’s a powder keg. And it went off on Jan. 6.”

The United States today is at a critical juncture, facing a window of opportunity to defuse extremist threats to democracy, Mr. Kilcullen said, but also the necessity to avoid an overreaction that could “massively inflame what we are dealing with.”

Solutions under new leadership?

When President Trump boarded Marine One on the White House lawn on the cold, sunny morning of Jan. 20, his departure removed one factor that has inflamed the nation’s extremist threat over the past four years – divisive leadership.

Mr. Trump’s favorable statements about (or reluctance to condemn) right-wing extremist groups and militias such as the Proud Boys, along with nods to white supremacists and far-right conspiracy theories, have buoyed and energized those movements, experts say. His exit shattered the QAnon myth that he would grab power with martial law, leaving his followers confused, disappointed, and “licking their wounds,” Colonel Wilkerson says.

Yet Mr. Trump is as much a symptom as a cause, experts say, of the wrenching political realignment unfolding across America, similar to historic shifts during the antebellum period, the 1920s and ’30s, and the late 1960s, when the New Deal coalition crumbled. Such regroupings generate conflict and require unifying leadership – such as that promised by President Biden – to overcome.  

This new era will call for “both political parties to spend more [when in power], if only to prevent social upheaval,” Professor Banerjee says. Reforms to electoral institutions may also be needed to bolster public confidence, he adds.

Steps for law enforcement

Much like after the shock of the 2001 terrorist attacks, the government may need to create an independent, bipartisan commission to provide a full accounting of the Jan. 6 insurrection at the Capitol and make recommendations for a comprehensive, intergovernmental response.

Law enforcement is likely to divert resources and manpower from fighting international to domestic terrorism, experts say. President Biden’s nominee for deputy attorney general, Lisa Monaco, has a counterterrorism background and would be well equipped to carry out such a pivot.

Partly this will require a policing of the police, since “you have some people in law enforcement who harbor some extremist views,” says Mary McCord, a former U.S. attorney in the Justice Department’s National Security Division who now teaches at Georgetown University Law Center. 

“Those are challenges that this [Biden] administration, states, local governments, and everybody will have to respond to.”

Some argue a federal statute that specifically criminalizes “domestic terrorism” is necessary, to give domestic agencies more investigative powers and authorities, despite the existence of ample criminal laws that allow for such prosecutions, including state domestic terrorism laws.

“The fact we can charge somebody with a state crime for assault and murder isn’t the same as saying under federal criminal law that person is a terrorist,” says Chuck Rosenberg, an attorney and former senior FBI official. “There ought to be a moral equivalency between international and domestic terrorism.”

Critics say a federal terrorism statute is unnecessary and would create a constitutional minefield and potentially be open to abuse. “It’s a slippery slope once you start creating political crimes,” says David Gomez, a national security expert who spent 28 years at the FBI. “It’s a razor’s edge for the Bureau to walk,” agrees Todd K. Hulsey, a retired FBI supervisory special agent.

Tackling the spread of violent domestic extremism will, for example, force courts to wrestle with profound questions such as how much the open carry of weapons intimidates and chills speech and peaceful assembly. 

“How do you meld gun rights laws with public protests, which are already tense affairs where people are agitated?” says Professor Zick, who is the author of a forthcoming book “Managed Dissent: The Law of Public Protest.” Gun-toting militias are transforming protest “into some kind of armed standoff,” he says. “Who wants to go and try to exercise their free speech rights in that context?”

The Supreme Court may have to take a merit-based Second Amendment case, which it has steadfastly avoided for over a decade, says Darrell Miller, a Duke University law professor and co-author of “The Positive Second Amendment.” “Justices can’t be ignorant of the fact of how guns are used publicly for good or ill,” says Dr. Miller.

Remember “the narrative that binds us”

In another striking sign of change, technology and social media companies such as Twitter, Facebook, and Amazon are taking far stronger measures to block or ban violent and dangerous content, steps some extremism experts say were long overdue.

Perhaps most important, the U.S. must address basic roots of unrest, namely the tribalism and polarization now deep-seated across society, including in the military, says counterinsurgency expert and retired Special Forces Lt. Col. Scott Mann, author of “Game Changers,” about defeating violent extremist groups overseas. 

“I never in my life thought we would have this conversation about the United States of America,” he says. “We just held our breath, wondering if there will be a peaceful transition of power.” 

Colonel Mann sees some similarities between group dynamics in the United States today and what he observed while deployed in Afghanistan, a status society where shame and honor prevail over social contracts and the rule of law.     

“It’s hard for veterans to know how to live in a country that is tearing itself apart,” he reflects. “The level of contempt citizens are showing is a level normally reserved for one’s enemies.”

Still, Colonel Mann says, the United States has overcome such divisions in the past, such as after the Civil War, and can do so again by refocusing on a common narrative of resolving conflicts through discourse and the Constitution. Americans must remember “the narrative that binds us, who we are as a people,” he says. “That is what it will take for us to all stand shoulder to shoulder.”

Editor's note: This story has corrected Professor Javed Ali's former title. He was a senior director for counterterrorism at the National Security Council.