This government creates all sorts of documentation and has all sorts of rules and regulations, and because America insists upon being the world's policeman, then it so follows, that there must be written instructions about how to best police other countries, insurgencies, and so forth, all contained somewhere within that government and its agencies, of which, since the CIA is responsible for foreign intelligence, it would seem logical to conclude that a competent and comprehensive department such as the CIA, would have at least one manual dealing with the assassination of those that represent a clear and present danger to the United States, in one form or another.
Not too surprisingly, there are documents purported to be legitimate USA documents in which, one is circa 1953, and entitled "A Study of Assassination" and another was obtained by wikileaks.com entitled "Best Practices in Counterinsurgency: Marking High-value Targeting Operations an Effective Counterinsurgency Tool" dated from 2009. Not only do these publications appear to be legitimate but the one dated from 2009, clearly shows at the top of the document that it is a publication of the Central Intelligence Agency. In addition, as they say, where there is smoke, there is fire, so, no doubt, there are in all likelihood even more documents dealing specifically with the assassination of foreign targets, by the CIA.
Perhaps for some people, all of the above might seem legitimate, as well as necessary, so that they do not question the need for assassinations and thereby implicitly accept such as the prerogative of their government. However, it must be recognized that the assassination of anyone or the deliberately harming of any target, by governmental forces so authorized by some national authority with the supposed power to legitimately do so, is questionable, at best, and morally wrong in virtually every possible case. For, if any government decides on their own volition that they have the right to assassinate any foreign national, then they have taken as an irrelevancy any international agreements that they are party to and have simply ignored such, or twisted such, in a manner which permits such assassinations, to be justified, and unimpeachable by any international consortium of member countries.
Further to the point, any document that is created that specifically deals with how to target and kill someone or to assassinate someone is, by its creation, setting the foundation for its usage, by the very creation of such. Additionally, those that are aware of how to best professionally conduct an assassination, and have hired specific people or devices to perform such assassinations, have thereby created assassins, in which, to believe that an assassin so created, is something that will be always controllable by that government, is misguided.
Rather, assassinations are a very dirty business, and should not be the legitimate business of any government of the people, by the people, and for the people. This country, has, quite unfortunately, created departments and the personnel within those departments that utilize all sorts of legalese to justify what is assassination, by calling it by different names, such as the targeting of enemy belligerents, with the belief that this government has the right to do whatever it finds necessary to do to defend itself, by using whatever force that they so chose, including assassinations, and have apparently written manuals so as to instruct their personnel on how to do exactly that.
All of this is true.