The result of Britain’s referendum on EU membership has strengthened far-right activism across Europe. In the UK there have been reports of public racist abuse, while far-right-leaning parties across the continent have taken advantage of the situation to call for their own referendums. There is a danger that an already polarised political environment will become even more broken with some individuals choosing a path to violence in response.

Extreme rightwing terrorism has been a growing problem in Europe for some time. A recent study by a consortium led by the Royal United Services Institute (RUSI) highlighted that when looking at the phenomenon of “lone actor” terrorism in particular (terrorist acts conducted by individuals without any clear direction from an outside group), the extreme right wing was responsible for as many as Islamist extremists. And not all were random one-off killers – Anders Breivik was able to butcher 77 people in a murderous rampage in Norway. What was particularly worrying was the fact that these individuals sat at the far end of a spectrum of extremists that included elements closer to the mainstream.

In the runup to conducting his act of terrorism, Breivik claimed to have attended protests organised by the English Defence League (EDL), a group he admired for its stand against what he perceived as invading Muslim hordes in Europe. Founded in the UK in response to a perceived refusal by authorities to clamp down on the noisy extremist group al-Muhajiroun, the EDL became a grab bag of far-right, anti-Muslim, anti-immigrant protesters who would take to the streets. It spawned imitators in continental Europe.

The emergence of the EDL, however, came at a moment when more established European nationalist groups such as Front National in France, the British National party (BNP) or the Austrian Freedom party, all became prominent in the public conversation. Far-right nationalist xenophobic sentiment has always been a part of the European conversation, but the strengthening of these groups highlighted how much the ideas they represented had started to slip into the political mainstream, largely off the back of anger with the usual parties of power. But while the far right tried to move itself into the mainstream, its violent edge remained, and as the European debate on immigration and Muslims has become more pronounced, there has been a growth in incidents of extreme rightwing violence.

The response from security forces has been mixed. While we have seen an apparent increase in extreme rightwing violence, there has been less attention paid to it by authorities. In the RUSI-led research, a particularly striking finding was that in about 40% of cases of far-right extremists, they were uncovered by chance – the individual managed to blow himself up or was discovered while authorities conducted another investigation. By contrast, around 80% of violent Islamist lone actors were discovered in intelligence-led operations – in other words, the authorities were looking for them.

But it is easy to understand why the extreme right wing gets overlooked. Most examples are fairly shambolic lonesome individuals whose efforts to launch terrorist plots seem amateurish at best. But they are still attempting to kill fellow citizens to advance a political ideology. And in the case of lone actors, they are at least as lethal as their violent Islamist counterparts – in our dataset of 120 cases, even when one removed Breivik as an outlier, the extreme right wing was as lethal as violent Islamists.

The concern from this phenomenon must now be twofold. On the one hand, the increasing mainstreaming of a xenophobic anti-immigrant narrative will feed the very “clash of civilisations” narrative that groups such as al-Qaida and Isis seek to foster – suggesting that there is a conflict between Islam and the west which they are at the heart of. It will only strengthen this sense and draw people towards them.

But there is also the danger of frustrated expectations. The reality is that notwithstanding a rise in anti-immigrant feeling in Europe, the migrants will still come. Attracted by the opportunity and prosperity they see in Europe (which is often a huge improvement on the environment they came from), they will come to seek low-paying jobs – jobs that western economies will still need to fill and are not taken by locals, which offer better prospects than where they came from. This economic dynamic means that people will not necessarily notice a dramatic change in their material environment. Foreigners will continue to come and will continue to be a presence around them – providing a community to blame when individual economic situations do not change or feel like they are getting worse.

Here lies one of the more dangerous sides of this new European political environment. A polarised society which does not appear to materially change – frustrating those who feel like they have expressed their political will only to find it unanswered. The result, unless handled properly by the mainstream political community, is a potential for violence that has already reared its head brutally on the European continent, and unless carefully checked will do so again.