The place they are coming from are a beehive full of terrorist. They can import trained specialists, intelligence guys or whatever recruiters or who knows what from that place...
I'm not saying most are terrorists there, in fact I think big majority are not, but majority in that are leeches that are looking for free givaaways. But my point is screen the shit them before letting in, they are coming from a biggest hotspot of terrorism on planet earth, so to think that from over a million there might be quite a few retards that want to train someone to blow up or do it themself is not such a far fetched theory.
I agree with you in principle namely that it is stupid to let in thousands of people into your country (let alone an internally open EU) without having the right vetting processes in place. This becomes more important when these people come from terror hotspots and when the terrorists themselves say they will sneak their guys in amongst the refugees. It is crazy that thousands from terrorhotspots are allowed in for life, when a tourist who wishes to visit the EU has to provide their passports, bank statements, undergo biometric test, provide proof of health insurance, proof of university enrollment or HR letter from employers, undergo background check, and provide the whole trip itinerary with hotel bookings and what not and still sometimes do not get the temporary tourist visa out of security concerns. I am not saying its unfair, I am saying it weird that with tourists the authorities give incredible attention to the security concern but completely disregard it with the refugees. So we do agree in principle.
However, I think all these visa security vetting processes can do is reduce the threat of incoming terrorists minimally. Other domestic policies should have a larger effect. The ghettoization of muslim communities has to be combated. Incoming refugees should be distributed across multiple towns and cities (they are here already so those who made it here are coming in sooner or later), they should be taught the language and provided support to integrate well with the society rather than live by themselves in a closed community. Mosques should definitely be monitored for hatespeech. If the friday sermons are anything like what I recall hearing in Egypt then they must be shut down. Policies of this type would alleviate some of the threat posed from internal jihadis but again it wouldn't cut it enough.
What the west has to do is go to war with ISIS, a serious war. What differentiates ISIS from any other terror group is that they were hoping to establish a state and they succeeded at doing so. They have established a Caliphate system that implements Sharia law, a system that we were taught is "the ideal" ever since we were kids. We were taught that this system produced unprecedented prosperity for the region, it broke the byzantine empire and the persian empire, it cast terror and commanded respect from the non-muslim empires, it was powerful, just, and prosperous for muslims and non-muslims under its sovereignty. It was the system ordained by good and its success in the past is proof of its divine origins.
ISIS are tapping into that sentiment and are re-establishing that dream world again. This sets them apart from any other jihadist group in modern history. They are controlling massive lands, and have established state institutions. They have their own regulatory bodies, tax collectors, judiciary, police force, military, legal code, a capital city, industries like oil and weaving, a department of foreign affairs, ministries everything that you need for a state. They are a state, a caliphate and they are striking fear into the hearts of the entire world. This gives them credibility and legitimacy as a true caliphate in the eyes of many. No wonder the jihadis in Sinai and in Libya (who were not part of ISIS) have pledged allegiance to them. This credibility is exactly what must be destroyed.
You don't destroy that by propaganda, the media cant even stop people from supporting Donald Trump despite their best smearing efforts. If you want to take away their credibility and stop their growing strength and popularity amongst muslims then you must cut off the head of the monster. Undo all the work that they have done. Take their capital city from them; take every big city of any symbolic religious, historical or even economic significance. They must be reduced to a mere group of jihadis trying to avoid arrest by the authorities
Destroy their institutions. Revert them back into a rebel underground group like any other terror cell, don't let them have a state. This takes full-fledged boot on the grounds war and it shouldn't take much if the US military is seriously involved and to finally put their big defense budget to work rather than just store advanced weapons in hangars and inventories. They have done it before to much more mature and richer states like Saddam's Ghaddafi's and others.
In my opinion this war is going to happen sooner or later. The west can have it now when ISIS is still small and weak and it would take 30,000 or so boots on the ground or they can wait until ISIS is bigger, has more credibility and support amongst muslims and have better funding and organizational skills to do more terror attacks. If they wait it will be a bigger war. They should kill the demon now before it grows. If they wait until their hands are forced it will be a massive war with much more than 30k boots needed on the ground.
So yes domestic policies and security policies are needed to reduce the threat but ISIS will only get better and more appealing if thats all what the west does. The only way is foreign policy: a serious war.