Targeted killing can have nothing more than detrimental effects in international relations. As a tool for foreign policy, it is more than shocking that certain governments (including our own United States government) have believed targeted killing to be a step forward in international relations. Dialogue should always be preferable to this tactic.
The murder of human beings, guilty or innocent, suspected or not, is never morally permissible under any circumstance, and targeted killing is one of the reasons we are so widely hated in the Middle Eastern region, and soon the whole world will turn against us. Diplomacy and discussion is the only way to handle foreign policy without becoming corrupted.
I do not usually like discussions of morals, because the conversations usually digresses into a bunch of what ifs and personal preferences and choices. I do not think killing is ever morally permissible. You are killing someone else. That is murder. But, I do think there are cases where it makes sense.
To me there is no difference between targeted killing and the death penalty. I don't support the death penalty, so I don't support targeted killing either. I understand that this may be necessary in some peoples eyes, but I certainly wouldn't want the burden on my shoulders. I think it is a very poor foreign policy tool.