The vast majority of these migrants come from war-wracked countries or economically desperate countries; look at Syria. Of course, this will require more taxes on the already burdened populace, but as more and more workers are integrated into the country, the gross domestic product will increase, and as the global economy changes in response to the growing BRICS economies, may just give the EU the upper hand it needs.
They should have a program that accommodates some refugees in need of serious support and are fleeing a war-torn country, but to just open the borders has been proven to result in absolute failure.
The plethora of "no-go zones" throughout Europe due to Sharia Law being implemented by massive numbers of migrants moving in all at once is evidence enough that opening the borders does not work.
The cultures which are incompatible are exactly that - incompatible. Western culture believes in equality and that violence doesn't have any place in political discourse, and Middle-Eastern culture (can't find the right word) believes in basically the exact opposite.
Acid attacks are on a rise, Sweden is now the rape capital of Europe, violence has risen exponentially, Cologne was the center of one of the largest mass sexual assault and rape sprees in history, the largest mass shooting in modern history took place in France, a truck was driven through almost 90 people - and this is all thanks to Europe opening its borders to refugees.
Have a program that helps small numbers of people integrate into society. Do not open the borders, as that has been proven to fail miserably. Poland has the right idea, and they just happen to be the only country in Europe that hasn't had a terrorist attack in decades.
In the interests of social cohesion and to avoid voting blocs arising which support cultural attitudes to gays and women that are incompatible with the dominant culture in contemporary Western democracies. Other cultural incompatibilities will become flashpoints if the number of migrants rises to the point where their attitude to gays and women is translated to new laws which counter the civil rights progress that has occurred in Europe.
There is less need for assimilation and less potential for conflict if migrants move to nations that share very similar cultures, social norms and customs.