"We begin our legal analysis with a consideration of section 1 119 of title 18, entitled 'Foreign murder of United States nationals.' Subsection 1119(b) provides that '[a] person who, being a national of the United States, kills or attempts to kill a national of the United States while such national is outside the United States but within the jurisdiction of another country shall be punished as provided under sections 1111, 1112,and 1113.' 18 U.S.C. § 1119(b). In light of the nature of the contemplated operations described above, and the fact that their target would be a 'national of the United States' who is outside the United States, we must examine whether section 1119(b) would prohibit those operations. We first explain, in this part, the scope of section 1119 and why it must be construed to incorporate the public authority justification, which can render lethal action carried out by a governmental official lawful in some circumstances. We next explain in part III-A why that public authority justification would apply to the contemplated DoD operation. Finally, we explain in part III-B why that justification would apply to the contemplated CIA operation. As to each agency, we focus on the particular circumstances in which it would carry out the operation."