MARY LOUISE KELLY, HOST:
Let's turn now to the topic of ISIS and money. ISIS, or ISIL as it's also known, needs cash to pay its fighters and pull off attacks like the ones last month in Brussels. That need presents an opportunity for counterterrorism officials trying to thwart Islamic State terrorists and trying to make it harder for recruits to do everything from paying for plane tickets to, say, renting an apartment in Brussels to buying supplies for bombs. One of the people leading the effort to drain ISIS coffers is Daniel Glaser. He is assistant secretary for terrorist financing. And we reached him at work at the Treasury Department. I asked him how ISIS gets its money in the first place.
DANIEL GLASER: So the main sources of revenue for ISIL are oil sales. We had estimated previously that they made approximately $500 million a year from oil sales. That number has dropped substantially over the past year. I think that could be attributed partially to the airstrikes. And I think that it could be attributed partially to the drop in the international price of oil, which complicates their business model, if you will.
I think that we've really over the course of the past year reduced ISIL's ability to produce oil by about 30 percent. And I think that their ability to profit may be down by as much as 50 percent.
KELLY: You mentioned airstrikes, and one of the more fascinating tactics of that the U.S. is employing is literally blowing ISIS cash to smithereens by targeting ISIS's cash depots. Do we know how much money has been removed from ISIS through that means?
GLASER: We estimate at least tens of millions, perhaps hundreds of millions of dollars have literally been incinerated through these airstrikes. Hundreds of millions of dollars is a substantial percentage of whatever their ultimate total budget is. It is by no means a silver bullet, and they still have plenty of money. But that's an important hit, and it's a really important development in the air campaign against ISIL.
KELLY: And I guess we should explain that this is especially painful to ISIS because ISIS is largely cut off from the international banking system. They're running a cash economy.
GLASER: Yes. We've worked very, very closely with the Iraqi government and the Iraqi Central Bank in particular to ensure just that. The real challenge that the Iraqi government faces is exchange houses. There's 1,900 exchange houses in Iraq, and we've worked very closely with the Iraqi Central Bank to make sure that those exchange houses don't provide a financial outlet for ISIL. And that's an ongoing effort that we have with them.
KELLY: All of that said, ISIS is still capable clearly of pulling off atrocious terrorist attacks, such as the one we saw last month in Belgium. Does that suggest there's still quite a long way to go?
GLASER: Of course there's a long way to go. This is going to be a long journey. But I think that on the financial side, we're progressing fairly nicely. ISIL still has the ability to move money. They still have the ability to generate money. And oil is not the only place they generate money from. They make perhaps hundreds of millions of dollars from taxing their population. And that's why we work so closely with the Iraqi government to try to dry up the liquidity that's entering ISIL-controlled territory. So there's a lot of different ways that money could come in, and we have to be careful about all of them.
KELLY: What are the big challenges that you're looking at next as you try to really - really bring their finances down - narrow them down to a trickle?
GLASER: You know, impacting what's going on within the territory that they control is always going to be a challenge. We could certainly do it militarily, but this is a large territory that they control. And the numbers that they're making have been so large in the past that even when I could come on and say we think that their revenue has been reduced substantially from taxation, from oil, there's still a lot of money left. And it's going to be - continue to be a real challenge for us to get at that money.
KELLY: Daniel Glaser is assistant secretary for terrorist financing at the U.S. Treasury Department. Thanks for taking the time.
GLASER: No, thanks for being interested. Transcript provided by NPR, Copyright NPR.