. >> professor elizabeth saunders, what is your back out? >> i teach in the political science department. my undergraduate degree was something quite different to was physics and astrophysics. please don't ask me any questions about that. i teach american foreign policy which is a wonderful course to teach. at the graduate level i teach ph.d. students. i study u.s. foreign policy and international security. >> your first book. >> it is. >> how did you go from astrophysics to a graduate degree? >> political science, i studied political science at yale university and had been fascinated by science and history. i certainly love to studying physics, but i also took a lot of courses in college on government and public policy. i started off thinking i might want to study nuclear weapons and then began to get fascinated combining to interests and i still do have a strong interest. but to become fascinated by the question of why in the post 9/11 world, a time when you would think we would have a pretty good idea of where threats came from and what t

talking with professors who are authors, and on the screen now 1 the cover of professor elizabeth saunders' book, "leaders at war, how presidents shaped military interventions." why use the word "interjengses"? >> guest: this is a book dealing with a particular question about the use of military force in american foreign policy and how they used military intervention as a tool in american foreign policy. these are wars of choice, not situations where you are dealing with a direct attack on your borders. these are using -- this is use military force to intervene in the internal affairs of another state, usually quite a distance away from the united states. the book is really dealing with the question of why we see certain kinds of military interventions under some circumstances rather than others, so i argue in the book there's really two models of intervention. there are what i call transformative interventions seeing the united states getting deeply involved in the domestic affairs of another state so we can think about the nation buildings intervention in the 1980s with haiti and the bul

what you are seeing on your screen now is that cover a professor elizabeth saunders book leaders -- "leaders at war: how presidents shape military interventions" professor saunders, why did you use the word intervention? >> this is a but primarily dealing with a very particular question about the use of military force in american foreign policy and specifically how presidents use military intervention as a tool in american foreign policy first. this is using military force to intervene in the internal affairs of another state, usually quite a distance away. the book is dealing with the central question of why we see certain kinds of military intervention is under some circumstances rather than others. i argue there are two models, transformative where we see the united states getting deeply involved in the domestic affairs of another state. we can think about the nation-building interventions of the 1990's in haiti in the balkans with the u.s. is really getting quite deeply involved in those states domestic affairs, building and rebuilding, changing their domestic institutions. on the