My God, how many IS fanatics are there already among the hundreds of thousands of migrants in Germany? Go on, admit it: You've thought that, too, even as paramedics and doctors in Paris fought to save the lives of seriously injured victims.

It positively leaps out at you: connecting the Islamist murderers from the Paris attacks to the migrants pouring into Germany, especially from Syria. Didn't they find a Syrian passport at one of the crime scenes, whose owner had been registered in Greece on October 3 and recorded several more times along the Balkan route?

Yes, that's absolutely true. It would, however, be foolish to make such a simplistic association between the shots fired in Paris and the refugees entering Germany.

Refugees as terrorists in disguise?

Nonetheless, we always fear the next attack. Since the bloodbath in Germany's neighbor, "our refugee problem" has been relegated to a footnote, for the time being. Accommodation problems, costs - all trivial compared to the horrific idea that there are undetected terrorists among us, ready and determined to do anything.

November 13 in Paris has brought German domestic politics more sharply into focus. More than ever, the question is: Should Angela Merkel change her policy on refugees? No, she should not! Not in essence, anyway.

That's because anyone who is already here and entitled to asylum cannot be sent back. But those who are still en route and seeking asylum do not necessarily have to settle in Germany. It's self-evident that the policy on refugees must be a European one, and that Germany can't be left to bear the burden alone.

Germany is allowed to expect solidarity in this, just as France can rely on the solidarity of its partners in the fight against terrorism. Because just like those who lost their lives or their health on Friday, the refugees from Syria, Iraq and Afghanistan are also victims of IS terrorism.

There is, of course, a residual risk that there are indeed jihadis in disguise among those who have already arrived. But they don't need to take the refugee route in order to get to Europe. They can turn up any time, anywhere.

Officials currently have 420 so-called "potential attackers" under surveillance in Germany; Europe-wide there are more than 3,500. There can never be 100 percent protection against these fanatics.

Watch out for returnees!

The biggest danger is the so-called returnees: young Muslims from Germany who have been recruited by ISIS, some of whom have been given highly professional training in the arts of warfare and of terrorism. Many of them are now back in Europe - including Germany - on kill missions.

They need to be identified and neutralized, also as a preventative measure. If someone was so much as present at the murders in Syria and Iraq of Kurds, Yazidis, and others by "Islamic State," they have, ipso facto, already committed a crime.

The German federal police aim to hire 3,000 new recruits, the Federal Intelligence Service more than 225, and the domestic intelligence agency, the Office for the Protection of the Constitution, more than 250. These are the right steps to take - measures that will also, as of today, restrict individual freedom.

But that is the price of security. We need more secret service people, not fewer. Liberal society will have to put up with that.

Europe must reinvent itself

After Paris, and amid the uninterrupted influx of hundreds of thousands of refugees - Muslims above all - the EU, too, is under pressure to take action. Solidarity with France is good, but it dwindles to a mere naïve gesture if there is not an acknowledgement, soon, that IS terrorism and the movement of people fleeing the region of the Middle East are a principle of cause and effect. Europe is in crisis; nationalistic politics of self-interest are in vogue.

This plays into IS's hands. The vast majority of people coming to Germany have escaped death at the hands of IS. Protecting them is a challenge for Europe, not just for Germany. So long as there are still those within the EU who fail to understand this, the expressions of solidarity with the French will prove mere hollow sentimentality.

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