The terror attack that killed more than 30 people in Brussels and wounded 270 more is just the latest in a string of attacks that have left European cities on edge.

The wave started when public transit facilities were targeted in Madrid in 2004 and London in 2005. More recently, a 2014 attack on a Jewish museum in Brussels, and the January and November 2015 terror strikes in Paris left many questioning the safety of the European people.

For the Record spoke with experts who said the attacks cast serious doubts on Europe’s policy of accepting immigrants from war-torn nations in the Middle East.