If you look at Cologne, the mayor welcomed 1000 undocumented migrants. She did not check to see if some were robbers or rapists, nor check if they were compatible with Western Culture. Move forward 10 days and there have been over 60 cases of sexual assault. There should be documentation and background checks of the people entering a country, without it you could be bringing in bad people. This is true for any group of people, but especially with cultures that do not hold the same values as the west.
According to the EU 21% of the people who entered Europe in 2015 were Syrian refugees. Most were economic migrants escaping poverty not refugees escaping war. Its the economic migrants who are causing a lot of the problems in Europe, not the Syrian refugees. With that being said anyone coming into a country should be screened to prevent Paris and Cologne like situations.
In today's world, countries need to be very careful accepting refugees. I think they should definitely employ more stringent screening to prevent social chaos. Accepting refugees is not always a popular thing to do. There are many people against it, so I think you definitely need to do it as safely as you can.
Whether or not you feel that the United States should allow refugees to find homage on our soil, it is undeniable that any country, the U.S. or any other, should absolutely employ very stringent screening processes. The processes are necessary to not only prevent social chaos, but to ensure the safety and security of the country's citizens. We unfortunately live in a world where terrorism runs rampant, and any precautions that can be taken to prevent it should always be taken.
Syria is a country in shambles, with no database with which to vet these "refugees". I agree they should vet them stringently, but I know that they absolutely cannot. Aside from the infrastructure problems that prevent vetting, there is also the fact that ISIS is printing fake passports and they say they are going to use them to infiltrate the "refugees" or invaders as I like to call them.
Countries accepting refugees should employ stringent screening processes in order to protect the residents of those countries. Refugees should be accepted and assisted, but not at the expense of harm to the residents of the host country. Refugees with extensive criminal histories and/or mental issues should not be allowed to enter the country.