The US doesn't even kill foreign leaders. Our intelligence service doesn't have the skills or appetite, let alone citizens. The resulting scandal would make the Church commission look like nothing, not to mention the impact on recruitment.
Yes, they only kill random fishermen in the Caribbean, foreign leaders get kidnapped and tried in kangaroo courts. Except Iranian leaders, those do get killed. But that's just the last 6 months.
Surely you've reached the conclusion by now that "resulting scandal" no longer steers policy, or even any noteworthy degree of public outrage.