Katherine Pickering Antonova is associate professor of history at Queens College, CUNY and author of "An Ordinary Marriage: The World of a Gentry Family in Provincial Russia."

The British showed the need for a united front against homegrown fascists like those who rallied in Charlottesville. (Evelyn Hockstein for The Washington Post)

The kind of domestic terrorism unleashed by neo-Nazis in Charlottesville last weekend is tragically not new to our political culture. But as we grapple with the aftermath of this horrific event, the United States is at a crossroads. How individuals, the news media and politicians respond matters. Will we, after a brief period of outrage, move on with politics as usual, or will we use this terrible moment to unite against extremism? Have we reached a tipping point?

In 1934, Britain was at a similar crossroads. That country also witnessed a violent rally that pitted fascists against anti-fascist demonstrators, propelling Britain into an active defense of its democratic institutions. The result: Britain kept its fascist party out of power and successfully defended itself against Nazi Germany during World War II.

President Trump has failed to unequivocally denounce the terrorists or fire the members of his administration who are sympathetic to white nationalism — people like chief strategist Stephen K. Bannon, deputy assistant to the president Sebastian Gorka and senior adviser Stephen Miller. The radical right continues to portray the neo-Nazi rally as a mere free speech demonstration. Both responses force Americans to confront the uncomfortable fact that fascism lives among us. It also suggests we have an imperative to take action, just as Britain did over 80 years ago, to prevent the spread and legitimization of these dangerous ideas.

Fascism gained support in Britain throughout the 1920s, culminating in the formation of the British Union of Fascists (BUF) by Oswald Mosley in 1932. Initially the BUF enjoyed prominent funding and support, most notably from Harold Rothermere, owner of the Daily Mail.

It built on native British movements like the “English Mistery,” a grass-roots organization that explicitly endorsed racism and eugenics and involved a number of high government officials. When Mosley spoke to followers at the Olympia stadium in London on June 6, 1934, the BUF had about 50,000 members. The Olympia rally, however, was the first time violence broke out, when BUF “Blackshirts” forcefully ejected groups of organized counterprotesters.

A week later, a 20-year-old aristocratic British fascist, Unity Mitford, wrote a letter to her sister Diana that captures some of the madness, and some of ordinariness, of Hitler’s appeal in British society at that time.

Unity had traveled to Munich because she wanted to see Nazi Germany up close. In her letter she describes meeting Hitler at a tea room. She was 20, but her letter sounds like it was written by a 14-year-old who just met Justin Bieber. She was so “terribly excited” she had forgotten her camera. “Trembling all over,” she couldn’t hold her cup of chocolate. She wrote, “It was all so thrilling I can still hardly believe it. … When he went he gave me a special salute all to myself.”

Unity’s letter also captures the significance of the Olympia rally for fascist supporters, which she was crushed to miss and described as “such heaven.” Unity was well aware of the rally’s violent conclusion when she wrote this. In fact, that was the appeal. It was a gleeful embrace of violence that characterized the fascist approach to politics: Violence proved dominance over “inferiors.”

In the aftermath of the rally, Unity was disappointed only in the reaction from people she had expected to be supportive. She wrote, “what an outcry in the papers, though!” referring to the reaction from conservative MP Bill Anstruther-Gray. Anstruther-Gray had denounced the Blackshirts in a letter to the editor of the Times, for which, Unity wrote, she was “longing to see him thoroughly beaten up. He does deserve it.” Anstruther-Gray had been present at the Olympia rally and condemned the BUF’s methods as a “deplorable outrage on public order.”

Anstruther-Gray was not alone. After Olympia, Rothermere and the Daily Mail also withdrew open support and the rest of the British press effectively boycotted Mosley, reporting only the continued violence that broke out at subsequent rallies but not details of his speeches. Newspapers that had previously been sympathetic — often catering to a public taste for appeasement of Hitler — changed their tune. British Blackshirts were branded as thugs.

That also made attending Mosley’s meetings much less comfortable for MPs and government ministers. It was only after this shift in the way fascists were treated in the press and in political discourse that the realities of the Nazi threat finally penetrated the British public, helping them to coalesce behind the war when it broke out in 1939.

The British and Americans often like to think we avoided fascist governments because of something special about us — that fascism just isn’t in our national character. But there isn’t a gene that prevents us from falling for bad political ideas. Rather, we avoided fascist takeovers in the past because individuals made certain decisions. Editors rejected further coverage of the charismatic Mosley. Reporters described the continued violence. Government officials stopped taking the BUF seriously.

Yes, Britain and the U.S. were better off than other countries after World War I and enjoyed stable, long-standing democratic systems. But it mattered that politicians, journalists and editors reacted to Olympia with strong condemnation. They said in effect: Political violence is a line we won’t cross.

Drawing that line is what made these societies a place where that line wouldn’t be crossed. “Democratic institutions” are meaningless unless the people in them consistently make responsible decisions.

Have we already passed that point, with the election of President Trump? His campaign regularly encouraged violence, racism and anti-Semitism: ideas and tactics central to neo-Nazi activists and on display in Charlottesville. To dial back from these extremes we need political leadership and we need the media — including social media companies — to take responsibility commensurate with their power. And those of us ordinary people who don’t want to live in a society that embraces violence and prejudice need to make our voices heard.