His Job Description? Protecting German Democracy. Literally.

NEUSTADT, Germany — Thomas Haldenwang, Germany’s domestic intelligence chief, frowned as he scanned the faded black-red-gold of the original German flag on display at Hambach Castle, where it was famously raised during a pro-democracy march in 1832.

Nearly 200 years later, tens of thousands of angry citizens are once again in the streets waving Germany’s national colors. But this time they are mostly marching against the democratic values their ancestors stood up for.

The irony of the moment was not lost on Mr. Haldenwang. His job is to protect those values and the constitution they’re enshrined in, literally: He runs the Office for the Protection of the Constitution, as the domestic intelligence office is known in Germany. Its mission is to detect anti-democratic actors and organizations and put them under surveillance.

“It worries me that our national symbols have been hijacked by the enemies of liberal democracy,” Mr. Haldenwang said in a recent interview at the castle — the site of the pro-democracy demonstrations in the 19th century — where he made a rare public appearance to discuss the threats to democracy in an auditorium filled with high-school students. “We need to claim them back.”

At a time when Russia’s war in Ukraine, a deepening recession and soaring energy prices have conspired to embolden the far right, Mr. Haldenwang takes his title very seriously. Just last week, his agency helped bust a plot to overthrow the government, in one of the biggest counterterrorism operations of postwar Germany, the second one this year.

“I do in fact see myself as a defender of democracy in Germany,” he said. “It’s my constitutional mission but it’s also a personal mission.”

Born in 1960, Mr. Haldenwang grew up in the western city of Wuppertal at a time when Germans were just beginning to reckon with their Nazi past. When he was 16, a young history teacher took his class to the memorial at Dachau concentration camp. The images of emaciated corpses seared themselves into Mr. Haldenwang’s consciousness and were one reason he volunteered to work in a kibbutz in Israel run by survivors of the 1943 uprising in the Warsaw Ghetto.

Many of those survivors refused to speak to the young Germans who had come to help clear rocks from an avocado field. Those who did insisted on speaking English.

For Mr. Haldenwang, it felt personal: His own grandfather had fought and died for Hitler’s army just outside of Warsaw.

“I was acutely aware of the guilt of Nazi Germany, the guilt Germans incurred at that time,” Mr. Haldenwang, now 62, recalled in a recent interview. “I understood then that we are the descendants and we bear a special responsibility for this to never happen again.”

“Never again” has become an integral part of Germany’s postwar identity, the only way forward for a nation seeking to rehabilitate itself from murderous terror state to worthy ally of a democratic West.

For Mr. Haldenwang, this mantra became a driving force.

The son of a textile executive and homemaker, he studied law and bought his first copy of the Constitution — a 1949 founder’s edition — in his early 20s, vowing to dedicate his life to serving Germany’s postwar democracy. Unlike many in his generation who opted out of military service, he served in the navy before joining the civil service. After the Berlin Wall fell, he was dispatched to the former Communist East to help build democratic institutions, before climbing the ranks of the interior ministry and intelligence service.

Mr. Haldenwang’s agency, which he has led since 2018, is a key pillar of what Germans call “defensive democracy” — a democracy equipped to defend itself against threats from within. Germany knows those threats better than any other Western democracy. Hitler’s Nazi party took power after democratic elections only to use that power to abolish democracy.

The authors of Germany’s Constitution gave the fledgling postwar democracy robust tools to make it last. One article allows a court to ban political parties deemed enemies of the constitution. Another stipulates that individuals can forfeit their constitutional rights when they use their rights to undermine the Constitution. There is even an article permitting armed resistance against a budding dictator should all else fail.

Mr. Haldenwang, who by now has 10 different editions of the Constitution on his shelf, likes to recite Article 1: “The dignity of human beings is unassailable.”

That, in a nutshell, is the North Star of his agency. “We are the early warning system of democracy,” Mr. Haldenwang said.

But critics say that when it comes to identifying far-right extremism as a threat, the agency has been late rather than early.

Until Mr. Haldenwang took over, Germany’s political establishment appeared to turn a blind eye to the far right. Since the fall of Communism, more than 260 murders by far-right assailants have been dismissed as single cases.

The most egregious failure was when a neo-Nazi terror group killed nine immigrants between 2000 and 2006 and went undetected until 2011, when it claimed responsibility itself. Worse, paid informers of the agency stand accused of helping the group. The day after the group was exposed, agency workers shredded a number of files in what still looks like a deliberate effort to cover up involvement with the terror group.

More recently, critics said Mr. Haldenwang’s predecessor, Hans-Georg Maassen, played down far-right violence during anti-immigrant riots in Chemnitz in 2018. He denied this but eventually resigned, and has been celebrated by neo-Nazis as a martyr and hero ever since.

During all those years, Mr. Haldenwang, already at the agency, never spoke up publicly. But as soon as he took over as president he raised the budget and the number of agents dedicated to the far right.

“We’ve gone from one extreme to the other,” said Michel Friedman, a prominent television host and former head of the Council of the Jews in Germany. “His predecessor personified the blind spot in our institutions towards right-wing extremism, and Thomas Haldenwang calls it the biggest danger to democracy.”

Mr. Haldenwang said he began to realize the severity of the problem during the refugee crisis in 2015-16, when he was vice president of his agency. A devout Christian and member of the conservative party, he had supported the decision by the then-chancellor, Angela Merkel, to welcome over a million refugees. He stood by her even when the heads of the federal police, foreign intelligence and interior ministry said her position endangered national security.

In one campaign by his church, his portrait appeared next to a Bible verse from Luke: “Be merciful, just as your Father is merciful.”

A vicious anti-immigrant movement with antisemitic overtones took hold, eventually propelling the far-right party, Alternative for Democracy, or AfD, into Parliament, the first such party to achieve this since the Nazis. Mr. Haldenwang was alarmed.

“That was a game changer,” he recalled. “From that moment, it was clear to me that we had to tackle this.”

Once in office, he wasted no time. On his watch, dozens of actors in an expanding far-right ecosystem known as the “new right” — a think tank, a magazine, a crowdfunding start-up and others — have been categorized as extremist and placed under surveillance. After Germany suffered three deadly far-right terrorist attacks, including the first far-right assassination of a politician since the Nazis, the scrutiny intensified.

Most strikingly, Mr. Haldenwang has placed the AfD itself under formal surveillance, one of the most dramatic steps yet by a Western democracy to protect itself from far-right forces. The party appealed, but lost. In March, the administrative court in Cologne confirmed the intelligence agency’s assessment of “anti-constitutional activities within the AfD.”

Mr. Haldenwang pointed out that German anti-democratic forces try to subvert democracy by co-opting its most treasured symbols — the flag, the Constitution and even symbolic locations like Hambach Castle.

Almost a century before Germany first established a democratic republic, 30,000 protesters marched up the hill to the castle demanding civil rights. More recently it has become a location of choice for the far right. In 2018, the AfD held a high-profile meeting there.

Earlier this year, far-right protesters draped in the German flag blocked the entrance to the castle and shouted down a descendant of Holocaust survivors who was handing out information on a local Nazi memorial.

Still, even as Mr. Haldenwang’s agency remains on high alert after this month’s nationwide raids against the group accused of plotting to overthrow the government, his trust in Germany’s defensive democracy remains unshaken.

He sees two ways of looking at the raids. “One is to focus on the very real threats to our democracy,” he said. “The other is to celebrate our institutions and security services for successfully defeating those threats.”

Christopher F. Schuetze contributed reporting from Berlin.