But refugees had nothing to do with the bombings in London or Madrid, Oslo or Brussels, Beirut and Ankara.
The continuing war in Syria means that there is no end in sight to the refugee crisis. Only a few EU countries -- Austria, Germany and Sweden -- have taken in very large numbers. Angela Merkel, the German chancellor who has been blamed by several leaders, especially in Hungary and Slovakia, for allowing this influx to happen in the first place because of her open-door policy, is holding firm to her decision. But even Merkel knows that the patience of her own conservative bloc and the public is not limitless.
For months Merkel has been asking the other 27 EU member states to share the burden of providing security and assistance to the refugees. For Merkel, it is a moral necessity and humanitarian obligation as much as a long-term economic and social one. Morally, it is clear. Europe cannot allow Jordan, Lebanon and Turkey to carry a burden that has become almost impossible for them to continue to bear.
Refugees and migrants also bring advantages.
Several EU member states, in particular Germany and Italy are facing a serious demographic crisis that will soon hit the Central European countries. These countries need young people to fill skilled and unskilled jobs. German companies in particular need scientists and mathematicians, engineers and IT experts.
The services sector too is desperately in need of people to look after the ever-growing aging population across Europe. Hospitals need nurses and doctors. The demand is growing. If Germany and other countries want to fill this gap, refugees and migrants could be a real assets for both sides.
In practice, it means putting in place an integration policy that gives newcomers to Europe a stake and sense of identity in their newly adopted country. Alas, most EU countries, particularly France and Belgium and Germany and Britain, each for different reasons, have been pretty miserable at integration.
But there are no quick fixes to integration.
Merkel understands this. In recent months, as refugees and migrants began to enter Germany, she made the integration of refugees one of her main priorities. Merkel said Germany had done a bad job of this when, during the late 1950s and early 1960s, it invited Turks but also people from Spain and Italy, to fill the labor shortage as Germany's Wirschaftswunder, or economic miracle took off. These newcomers were called Gastarbeiter, or guest workers.
In the case of the Turks, it was assumed they would return after a few years so no effort was made to integrate them or indeed other ethnic communities that were later to come from Middle East countries. Most remained.
Merkel's grand coalition of conservatives and Social Democrats recently introduced sweeping changes to facilitate integration. Children from the age of three years must have a place in a state-run child care center or kindergarten. It is there that integration begins.
As for the many young (mostly male) refugees seeking asylum in Germany, according to the federal office for Migration and Refugees, 30% of the registered Syrian asylum seekers have a university or equivalent education and a quarter have a high school diploma. The opportunities are just as great as the challenges in integrating them.
Besides the need for housing, integration will demand an infrastructure of language teachers, places at schools from elementary right up to high school, company-training schemes, jobs, community support and a plethora of other facilities required to make this work.
However, despite the advantages of integration, there's backlash. Populist parties across Europe have been quick to link the terrorist attacks to the refugee crisis that some U.S. presidential candidates have also exploited.
Along with Merkel, French president Francois Hollande and head of the European Union Commission Jean-Claude Juncker have strongly criticized such a linkage. These leaders fear a backlash not only against the refugees but also against the Muslim communities across Europe.
Populist parties are already calling for the suspension of the Schengen system that abolished border controls between both EU countries. In cases of emergency, the Schengen policy, named for the 1985 agreement that dropped borders in Europe, can be suspended. But that will only help so far if the intelligence and security services in the EU countries are prepared to radically improve their level of cooperation. As it is, such cooperation and coordination is very weak, something of which France is acutely aware. Just look at how the perpetrators of the Paris attacks could go back and forth the border between Belgium and France even though they were checked.
Globalization is Europe's daunting challenge. No border controls can prevent the infiltration of propaganda and the proselytization of people. Controls can hinder terrorist attacks but EU leaders know there is no such thing as 100% security. Europe now faces a choice between confidently believing it can protect its citizens or to give in to fear and batten down the hatches.