As Siblings Again Unite to Unleash Terror, Experts Ask What Drives Them

By JIM YARDLEY, RUKMINI CALLIMACHI and SCOTT SHANE from NYT World http://ift.tt/1VGSI1D
via IFTTT Khalid and Ibrahim el-Bakraoui join a list of brothers involved in nearly every major terror attack on Western soil since three sets of Saudi siblings helped carry out the 9/11 attacks.