Demetrios Papademetriou of the Migration Policy Institute says problems with Belgium's migration policy go back decades — and have implications for domestic terrorism.
Belgian authorities have charged two men with terrorist offenses and are continuing to question others in relation to Tuesday's bombings of the main Brussels airport and a city metro station.
A third man has been charged in connection with an alleged plot to launch a new attack in Paris. Meanwhile, a "march against fear" planned in Brussels on Sunday has been called off.
A local leader of Germany's far-right NPD party, which has campaigned for closed borders, crashed his car. NPR's Scott Simon reflects on the irony of what happened next: refugees stopped and helped.
Turkey faces criticism for border policies allowing jihadists to flow back and forth from Syria. But it deported one of the Brussels bombers in 2015, and says Europe failed to take warnings seriously.
As people continue searching for their loved ones, they are turning to social media for help. One site, Trello, lets friends and family keep an active list of those who remain unaccounted for.
The pontiff is marking Good Friday with a traditional services, but on Holy Thursday, he broke with tradition by washing the feet of migrants of many faiths.
The Molenbeek district of Brussels is home to many of the terrorists who plotted the Paris and Brussels attacks. Its people are saddened, horrified and turning inward after this week's carnage.