By SETH J. FRANTZMAN

Why wasn’t Salman Abedi stopped before the Manchester bombing? Many are asking this question and have pointed out he was a “known wolf.” People who he knew in his community had warned authorities. His local network consisted of almost a dozen individuals. In many cases terror attacks across Europe have been carried out by “known wolves,” men whose far right Islamist views and threats were known to security services. Some had been monitored and the monitoring had stopped. Some had travelled to Syria and back and even been sent back by Turkey. Many countries had received warnings from abroad about the “known wolves,” from other intelligence services.

So why aren’t they stopped? Because of the sheer numbers of them. In the UK intelligence officers have told reporters that there are more than 23,000 jihadists and extremists in the country, of which 3,000 are actively monitored. When politicians warn that terrorism is just part and parcel of life and that people must “carry on” amidst the threat it is because they know the threat. Homeland Security Secretary John Kelly said in late May that people would “never leave the house,” if they knew what he knew about the number and extent of threats. “It’s everywhere. It’s constant. It’s nonstop…the good news for us in America is, we have amazing people protecting us every day. But it can happen here almost anytime.”

In Europe in wake of the threats, soldiers and police are a regular feature on streets, in airports and elsewhere. There is a state of emergency in France, with no end in sight. Around 5-6,000 EU citizens joined ISIS and other jihadist groups in Syria and Iraq between 2014 and 2016. In February 2016 experts warned of 5,000  ISIS members who might be in Europe having served in Syria and Iraq. Others warned that after the Mosul offensive began more would return. Sir Julian King said there were 2,500 fighters from EU countries in the combat zones.

The number of Europeans radicalized after ISIS came to the fore is immense. There were 600,000 Twitter accounts shut down associated with Islamist extremism in the last two years.  Per capita, Belgium and Denmark produced the most extremists, but the largest numbers come from France, Germany and the UK. They also come from Sweden and elsewhere. Radio Free Europe has a handy map. One third who went to Syria and Iraq returned.

Given the 23,000 jihadists and Islamist extremists in the UK, the numbers across Europe, especially in major far-right Islamist producing countries, such as France, Belgium and Germany, likely top over 100,000. Europe has produced large numbers. That is approximately the same number of members the Nazi party had in 1929. This is the reality of the far right Islamist threat. Think of the very dangerous jihadists like the SS portion of the Nazi party, which numbered only 3,000 in 1929, similar in number to the high risk extremists being tracked in the UK.

How do you stop “known wolves” when there are a hundred thousand of them? How do you stop that when there are another hundred thousand or several million abroad? It is true that the number of extremists is small, but you don’t need very many to spread terror and murder and havoc. You also don’t need very many to overwhelm the ability of the security services to track them all. Surveys show that in most countries support for ISIS is very small, numbering less than ten percent in 2015. But 2015 was the year that ISIS was broadcasting beheadings and was boasting of genocide and mass destruction of minorities. Yet in a Pew poll in many countries 10% said they supported it, knowing all this. If 10% support Nazis or the KKK and genocide, you have a problem. And that doesn’t include the pool of extremism around the open supporters of ISIS. ISIS is just a recent iteration of various far right Islamist hate groups.

Until Europe figures out how to reduce the hate, and reduce even the 1% or 10% who are far right violent Islamists, to .01%, the number of “known wolves” will remain or grow. Since 2001 when focus began to fall on European jihadism, there has been a massive increase in the number of extremists. Europe has exported jihadist hatred on an unprecedented scale. It has become a home for hate preachers who use “free speech” to recruit for ISIS and spread intolerance. Oddly the same incitement laws that convict others of racial hatred violations don’t seem to apply to these far rightists. Europe also took in many jihadists who fled their home countries to Europe, especially from Egypt, Jordan and elsewhere. Europe became a breeding ground for innovative jihadist networks, recruitment, strategy, and transit. Unfortunately this fueled ISIS and helped lead to genocide in Iraq and the trade in Yazidi women by EU born jihadists. There has been no concept of how to reduce this in Europe, only more security, more tracking, more police and soldiers. But if the far right Islamist hatred is not reduced, it isn’t clear how the known wolves will be.