The migrant problem

What is it that's sparked off the sudden angst about the refugee crisis? Refugees from Syria have been struggling to find homes in other countries for three or four years. Migrants have been invading Hungary for at least a couple of years (to such an extent that there's now a fence along the Hungarian border), and Sweden has been absorbing migrants for much longer (and is now struggling with the cultural difficulties of a people who won't assimilate).
Australia has been dealing badly with boat...