The idea has gotten traction ahead of Saturday's EU summit as a way to allow the union's members to integrate at paces they are comfortable with. But it's a contentious issue.
The Netherlands is one of Europe's most liberal countries – and home to one of its most ardently anti-Islam politicians, Geert Wilders, who could capture the most seats in March 15 elections.
With right-wing parties set to do well in elections in the Netherlands, France, and Germany this year, many are concerned about a Europe-wide populist swing. But the EU remains popular.
Prime Minister Renzi resigned after Italians rejected his constitutional reforms. Experts attribute that in part to Donald Trump's election – which could upend elections in France, Germany, and the Netherlands next.
On the campaign trail, President-elect Trump repeatedly challenged the status quo regarding key US allies, including NATO, Japan, and South Korea. But his actual intentions are unclear.
If Germany's refugee crisis last year played out at borders and shelters, this year the drama has shifted to the school building – and could determine how well refugees integrate.