ROBERT SIEGEL, HOST:
New York Times correspondent Rukmini Callimachi has been analyzing the tradecraft of the terrorists who executed the attacks in Brussels and the November attacks in Paris, and she joins me now. Welcome to the program once again.
RUKMINI CALLIMACHI: Thank you for having me, Robert.
SIEGEL: First, the Brussels attackers - what conclusions have you drawn, first, from that blurry photo of three people at the airport?
CALLIMACHI: The first thing that we notice about these people from the photo is how calm they appear. They're walking, you could say, almost casually, relaxed into the entryway of the airport. You can imagine that they're just people setting off on a trip and not bombers that are about to blow themselves up. This we've seen over and over again with these ISIS operatives. During the November 13 attacks in the Comptoir Voltaire bistro in Paris, the witness statements stated that the bomber walked in, smiled, calmly looked around him, excused himself for the noise he had caused, and then pushed the detonator.
SIEGEL: You've written in The New York Times about the use in the Paris explosions of a substance called TATP. And, again, stories of that have been found in the searches in Brussels. What's different or interesting about TATP?
CALLIMACHI: TATP has very much become the signature explosive that ISIS's external operations branch seems to be using in Europe. The reason that we're seeing it is TATP is made from two ingredients, acetone and hydrogen peroxide. Hydrogen peroxide, that comes from hair bleach, and acetone is found in nail polish remover. It's very, very hard for governments to put in trip wires that would alert them to the purchase of these ingredients. These are ingredients that you can buy, you know, in a place like Home Depot or in a beauty supply shop and then return home and bake the bomb.
SIEGEL: Before the Brussels attacks, you did reporting about how the Paris attackers had communicated among themselves. As you tell it, they were extremely disciplined in keeping their communications secure. How did they do that?
CALLIMACHI: Abdelhamid Abaaoud, as you'll recall, was considered the architect of the Paris attacks. When his body was found, they found near him literally dozens of disposable cell phones that were still inside their wrapper. They hadn't even been used. And at different sites where they carried out their killings, the same thing. The police found burner phones - phones that had been activated hours, sometimes minutes before the attack. From what we can tell, they only used these phones and then the phones that they took from their hostages inside the Bataclan in order to communicate with each other, with the police and as well as with accomplices that have not yet been caught. This, to me, points to the evolution, the arc of ISIS's external operations arm. Earlier, in 2014 and 2015, a number of plots were foiled, specifically because the fighters made really stupid errors. For instance, Ibrahim Boudina, who was arrested in the city of Cannes, had voluminous Facebook chats with various friends of his, which allowed authorities to figure out what he was doing.
SIEGEL: Given the practices of these people that you have reported about from France and what you've learned from Brussels, is ISIS or the people who are allied with ISIS, are they now ahead of law enforcement at this point? Is there one of those moments were they just have the advantage?
CALLIMACHI: It certainly seems that way. You could say before November 13 the authorities had not acknowledged and had not really realized the scope of the enemy that they were fighting. After November 13, after 130 people are gunned down and blown up in bars and stadiums and concert halls in Paris, certainly, at that point, the authorities have been put on notice. And the fact that Brussels was able to happen - and from everything we know, it's the same cell that caused Paris - the fact that it was able to happen just, you know, four or five months later is indicative of the fact that this is now out of our control.
SIEGEL: That's correspondent Rukmini Callimachi of The New York Times. Thanks for talking with us again.
CALLIMACHI: Thank you for having me, Robert. Take care. Transcript provided by NPR, Copyright NPR.