ABIGAIL BLANCO: So what a lot of people don't think about with respect to foreign intervention is the idea that the tools and processes that are developed as a part of foreign intervention can come to be used domestically. So people might not associate, for example, things like the use of drones domestically within the United States or unmanned aerial vehicles, torture in U.S. prisons, or things like the militarization of domestic police as consequences of foreign intervention. But these are the exact types of tools developed as a part of intervention abroad that then wind up being used back home. My coauthor, Chris Coyne, and I term this phenomenon the boomerang effect.

So the big question or what it is that we seek to do is to identify how it is that those tools, which were once exclusively used abroad come to be used back home. So we do this by looking at or identifying what we call the three channels of the boomerang effect. The first of these channels is what we call the human capital channel. You can think about human capital simply as the skill sets that an individual possesses or develops as part of their job. So students, for instance, are hopefully developing human capital as they go through their course of study. People, when they go and they take different jobs, are adding to their human capital. This is no different than when individuals are involved in the preparation for or execution of a foreign intervention. The critical piece is that once that intervention or that person's part of the intervention is concluded those skills that they've developed don't magically disappear. They stay with them.

And so those skills are then brought back with that person and integrated into their future endeavors whether those are in the public sector or in the private sector. The second channel that we identify is what we refer to as the administrative dynamics channel. So perhaps the easiest way to think about this is to think about the different organizational structures in which people have operated throughout their life. So people might be familiar with the administrative dynamics of education for instance. They know that overarching structure and how it works. Or if you go to work at a variety of different companies those have different administrative dynamics. The administrative dynamics that are often associated with foreign intervention so those that are highly bureaucratic, those that are very militaristic again become a part or people get used to operating within those dynamics and then are able to import those types of administrative structures into again a number of domestic institutions.

The last channel that we talk about as part of the boomerang effect is what's referred to as the physical capital channel. So if human capital are the skills that a person develops, physical capital are just those actual physical like tools that people develop as a part of foreign intervention. So these might be things like surveillance techniques. They might also be things like unmanned aerial vehicles or particular types of weapons. So again when individuals are completed or they're finished with their part of the foreign intervention they like to use or continue to use those tools that they've developed. And so we see an integration of the tools of foreign intervention into domestic operations.