Recent terror attacks carried out by radicalised white men in Western countries should be a “wake-up call” for Australia to take right-wing extremism more seriously, national security experts warn.

The caution follows Thursday’s terror attack in Germany by a lone gunman who live-streamed himself killing two people after attempting to enter a synagogue where dozens were observing a Jewish holiday.

In the video, which was uploaded to video game site Twitch but has since been removed, the 27-year-old German suspect is shown making anti-Semitic comments before driving to the synagogue in Halle and shooting at its door.

Frustrated after failing to get in, the gunman allegedly shot dead two people nearby – a woman near the synagogue and a man in a kebab shop.

German media said the attack was likely motivated by right-wing extremism.

It’s not just European countries that are under threat by lone-wolf white supremacists.

Last year in the United States, almost all 50 terrorism-related deaths involved right-wing extremism, according to the Anti-Defamation League (ADL).

In August, a lone gunman motivated by white nationalism allegedly shot and killed 22 people and injured 24 others in El Paso, Texas.

One day later in Dayton, Ohio, another young white man allegedly shot and killed 10 people, including himself.

Data from the ADL’s Centre on Extremism shows 73.3 per cent of all extremist-related fatalities in the US over the past decade can be linked to domestic right-wing extremists, while just 23.4 per cent can be linked to Islamic extremists.

Deakin University terrorism expert Greg Barton said the rise in global alt-right terror attacks, including the Christchurch shooting in March that killed 51 Muslim worshippers, should be a “wake-up call” to the spread of white supremacism in Australia.

“It’s all part of a conversation that’s happening around us, whether it’s in public life, question time in Parliament, an opinion column or on a football show,” Professor Barton told The New Daily.

“There is a discourse that involves hatred, public bullying behaviour and making people scapegoats, which gives a licence to people like (alleged Christchurch terrorist) Brenton Tarrant to do something awful.”

Mr Tarrant, a 28-year-old Australian, has pleaded not guilty to 51 counts of murder, 40 counts of attempted murder and one charge of terrorism.

Professor Barton said talk of African gangs running around Melbourne was “dangerous”, even if it was just a scare tactic used by politicians, because it played into the idea that dark skin – the ‘other’ – was a threat to white families.

“Most people who agree with Pauline Hanson about Australia being ‘swamped by Asians’ or ‘flooded by Muslims’ won’t carry out these attacks … but the more toxic our public discourse is, it’s reasonable to assume it’s more likely there will be another attack,” he said.

Of the 17 planned major terrorist plots disrupted by Australian authorities since 2014, one was planned by an Australian right-wing extremist.

Jacinta Carroll, a senior counter-terrorism researcher at the Australian National University’s national security college, said while right-wing extremist views in Australia were only held by a “small number of people” compared to radical Islamist views, they still posed a serious threat.

“The language of far-right extremist groups in Australia – from what we can see from their public profiles – borrows strongly from that used by current European and US far-right groups,” Ms Carroll said.

“We’ve already seen an increase in their attempts to infiltrate organised politics, such as when (far-right nationalist group) the ‘Lads Society’ tried to infiltrate the Young Nationals.”