As Micah Zenko of the Council on Foreign Relations writes in a post at his blog Politics, Power, and Preventive Action (thanks to the Progressive Realist for directing us to it):

After following this program closely for the past half-dozen years, I have stopped being surprised by how far and how quickly the United States has moved from the international norm against assassinations or “extrajudicial killings.”

He writes that, in an October 23 Washington Post article Plan for hunting terrorists signals U.S. intends to keep adding names to kill lists, reporter Greg Miller

… underscores the cementing of the mindset and apparent group-think among national security policymakers that the routine and indefinite killing of suspected terrorists and nearby military-age males is ethical, moral, legal, and effective (for now).

But the “for now” can soon be dropped because of

… the increasing institutionalization—“codifying and streamlining the process” as Miller describes it—of executive branch power to use lethal force without any meaningful checks and balances.

In fact, it’s a significant departure recent history. As Zenko reminds us, in 1975, a

… U.S. Senate Select Committee investigation, led by Senator Frank Church … implicated the United States in assassination plots against foreign leaders—including at least eight separate plans to kill Cuban president Fidel Castro [followed by] President Ford’s Executive Order 11905: “No employee of the United States Government shall engage in, or conspire to engage in, political assassination.”

Thus was

… opposition to assassination was widely held and endured throughout the Ford, Carter, Reagan, Bush, and Clinton administrations through 1999 for the following reasons.

In a quote from his book Between Threats and War: U.S. Discrete Military Operations in the Post-Cold War World (Stanford Security Studies, 2010), Zenko expands on that.

Assassinations ran counter to well-established international norms, and were prohibited under both treaty and customary international law. … weakening the international norm against assassinations could result in retaliatory killings of American leaders, who are more vulnerable as a consequence of living in a relatively open society. [Also] the targeted killing of suspected terrorists or political leaders was generally considered an ineffective foreign policy tool. An assassination attempt that failed could be counterproductive, in that it would create more legal and diplomatic problems than it was worth. An attempt that succeeded, meanwhile, would likely do little to diminish the long-term threat from an enemy state or group.

“Finally,” he writes, “the secretive and treacherous aspect of targeted killings was considered antithetical to the moral and ethical precepts of the United States.”

Also, Zenko writes, it is

… notable that Miller does not find officials worried about the legality, congressional oversight, transparency, or precedent setting for future state and nonstate powers wielding armed drones.

In other words, their shortsightedness is disturbing. It might behoove them to read Daniel Suarez’s crackling new techno-thriller Kill Decision (Dutton Adult), in which drones are programmed to make their own decisions about what — or, to be more exact, whom — to attack.