There have been several interesting stories about the cost of imprisonment, torture, killing and assassinations in the U.S.'s War on Terror. For example, in Afghanistan one often hears of an ineffective criminal justice system causing the U.S. military to release captured militants in the hopes that they can kill them next time. Similarly, this news article discusses the Obama administration's increased reliance on assassination attempts in, for example, Yemen, Afghanistan, and Pakistan.
Corrections suggests that this is in accordance with the Obama administration's decreased reliance on torture and the substitutability between targeted assassinations and capture and torture. This is depicted graphically below (click to enlarge). The straight red line depicts the Bush administration's capability to substitute capture and torture for assassinations. The curved line depicts their preferences, and the red dot depicts the best mix of capture and killing. We can imagine that the Obama administration through rhetoric has decreased its capacity to capture and torture terrorists (if only due to political ramifications). They retain the same ability to kill as the Bush administration, so their budget line is the straight blue line. If killings and assassinations are substitutable enough (for example) then it's possible the Obama administration will not only substitute away from torture and toward assassination but will actually have more assassinations (rather than less of both), which can be seen as the blue dot.