- Peter Bergen: Terrorists used an unstable compound made from household ingredients
- He says authorities in the United States and other Western countries need to be on the lookout for bulk purchases
Peter Bergen is CNN's national security analyst, a vice president at New America and a professor of practice at Arizona State University. He is the author of "Manhunt: The Ten-Year Search for bin Laden -- From 9/11 to Abbottabad."
(CNN)French prosecutors say the bombs used in the terrorist attacks in Paris on Friday were made from TATP, a fact that yields important clues about the way the plot was planned and executed.