The investigation into the motive behind the shooting deaths of nine people in Munich will not yield quick answers. The attacker, an 18-year-old German-Iranian who had lived in Munich for at least two years, does not fit into the usual categories of attackers. His Iranian roots rule out links to Daesh or Al-Qaeda. He might have been unstable but after killing himself at the end of his rampage, his state of mind might never be known. And even if he was deranged, it is difficult for somebody who is disturbed to carry out such an assault. What is the only truth so far is that this was the third attack on civilians in Western Europe in just over a week, following the truck attack in Nice which killed over 80 people and a teenage migrant who stabbed and injured five people on a train in Bavaria. The Nice tragedy was the third major attack on French soil in the past 18 months, after the Daesh carnage in Paris in November last year and the shootings at satirical magazine Charlie Hebdo and a supermarket in January 2015. In March this year, Daesh claimed suicide bombings at Brussels airport and a city metro station that left 32 people dead. And the day of the Munich attack, coincidence or not, was the fifth anniversary of the massacre in Norway by Anders Behring Breivik, who killed 77 people. The attacks all amount to Western cities and streets under siege and locked down, where elite anti-terror units are either scrambling to capture attackers or are positioned strategically for the protection of citizens who are beginning to see that shopping, dining out and simple strolls have become a risky proposition. The Munich attacker did reportedly scream out something about hating foreigners. If so, that is another threat: the far right, which for years has been warning against "the Muslim danger" and calls to expel foreigners from Germany. Incidents of physical violence against immigrants and the torching of immigrants' shelters are not rare in Germany. Attacks like the one on Friday may bring out of the woodwork extremist neo-Nazis who will feel confident enough to harm innocent immigrants just because of their skin color or religion. Germany has so far avoided the devastating radical Islamist attacks that have struck in France and Belgium but Germans certainly have a cause for concern. Among the more than one million refugees who entered Germany legally and illegally in the past few years are many who are unknown to the authorities. More than three-quarters of them crossed the border with no passports or other forms of identification. Technical and bureaucratic constraints make it impossible to systematically register all of the people who poured into Germany with Chancellor Merkel's welcome. Even if only a few of the masses who have made their way to Germany in search of a better life for themselves and their children have fallen under the radar, that's enough to keep the German authorities and the public awake at night. These attacks in Germany have shown how little Germany really knows about the refugees it is sheltering. In many cases, the government appears to have simply given them the benefit of the doubt. Germany, like many other countries, has not yet woken up from the sweet illusion that its streets, squares and markets – as well as trains, buses and the rest of its public space – are still safe to use. The country that took in over a million refugees has been lucky so far but the double attacks this week could be a harbinger of much worse to come. The direction is clear. From now on, Germany will not be immune to lone-wolf terrorists who for whatever reason head out to the street to attack innocent people who were in the wrong place at the wrong time.