"Why stopping Terror attacks against Soft Targets is so hard" PBS NewsHour 5/23/2017

Excerpt

SUMMARY:  What does the deadly attack at an Ariana Grande concert in the United Kingdom mean for the global fight against terrorism?  Hari Sreenivasan gets analysis from Alexander Meleagrou-Hitchens of George Washington University, and Michael Leiter former director of the United States National Counterrorism Center.