Since the late 20th century, the legal status of targeted killing has become a subject of contention within and between various nations. Historically, at least since the mid-eighteenth century, Western thinking has generally considered the use of assassination as a tool of statecraft to be illegal. Some academics, military personnel and officials describe targeted killing as legitimate within the context of self-defense, when employed against terrorists or combatants engaged in asymmetrical warfare. They argue that drones are more humane and more accurate than manned vehicles, and that targeted or "named killings" do not occur in any context other than a declared state of war.
Scholars are also divided as to whether targeted killings are an effective counterterrorism strategy.