When can a government kill its own people?
The straightforward question has anything but a simple answer, especially for the government of a nation founded on inalienable rights to life, liberty and the pursuit of happiness.
Monday's news that the Obama administration is considering a military hit on an American terrorist raises anew the issue of what justifies such a step, according to both the law and the public conscience in an era of political, social and technological evolution.
"America's legitimate claim of self-defense cannot be the end of the discussion," President Barack Obama said last year when he announced new guidelines on drone strikes that target enemies for killing. "To say a military tactic is legal, or even effective, is not to say it is wise or moral in every instance. For the same human progress that gives us the technology to strike half a world away also demands the discipline to constrain that power -- or risk abusing it."
The American Civil Liberties Union contends the administration abuses its power, particularly when it comes to drone strikes that have targeted foreigners and in some cases, American citizens.
"Even in the context of an armed conflict against an armed group, the government may use lethal force only against individuals who are directly participating in hostilities against the United States," the group says on its website. "Regardless of the context, whenever the government uses lethal force, it must take all possible steps to avoid harming civilian bystanders. But these are not the standards that the executive branch is using."
Here are questions about what the government is doing, with explanation of why and arguments against:
1) What does targeted killing mean, and how widespread is it?
After the September 11, 2001, terrorist attacks on the United States, a traumatized nation responded with new laws that greatly expanded the government's power to fight terrorism.
Wars were launched in Afghanistan and then Iraq, and the national intelligence system expanded to new capacity disclosed in last year's classified leaks by former National Security Agency contractor Edward Snowden.
Part of the expanded powers included legal authorization to target terrorists defined as enemies of the state -- people determined to be fighting a war against America.
The CIA and the military have used drones and covert missions to take out such targets, including drone strikes that killed U.S. citizen Anwar al-Awlaki, a wanted terrorist, and three other Americans.
Unofficial estimates based on reports by human rights groups and media accounts indicate the Obama administration has carried out hundreds of drone strikes that have killed hundreds and perhaps thousands of people, including terrorists and civilians, in an escalation of the practice started by the Bush administration.
Most have occurred in Afghanistan, but others have taken place in countries where no ground war was occurring including Yemen, where al-Awlaki and the two other Americans died in 2011.
2) Is it legal for the government to target and kill people?
In his May 2013 speech at the National Defense University, Obama proclaimed the practice completely legal.
"Under domestic law, and international law, the United States is at war with al Qaeda, the Taliban, and their associated forces," he said. "We are at war with an organization that right now would kill as many Americans as they could if we did not stop them first. So this is a just war -- a war waged proportionally, in last resort, and in self-defense."
Critics, however, say the government oversteps the legal boundaries of the Constitution and international law, particularly by making decisions on targeted killings in secret without going before any court.
"The result is that the public remains in the dark about how exactly U.S. policy governing targeted killings is operating, under which legal authorities, and who exactly are its victims," said a letter to Obama in December from nine rights groups.
Hina Shamsi, who directs the ACLU's National Security Project, told CNN that the Obama administration was "fighting hard" to prevent a judicial review of the strikes that killed al-Awlaki and the other Americans, including the terrorist's 16-year-old son.
Until allegations in classified documents can be assessed in court, she said, the question of whether they amount to real evidence remains unanswered.
Shamsi called the U.S. actions "one of the most extreme and dangerous forms of authority that the executive branch can claim -- the power to kill people based on vague and shifting legal standards, secret evidence and no judicial review even after the fact."
In 2010, a federal judge in Washington noted the government would need permission from a federal court to wiretap al-Awlaki, but that no such court process existed in order to kill him.
Rejecting an effort by al-Awlaki's father to block his son's possible extrajudicial killing, U.S. District Judge John Bates called it "somewhat unsettling" that a president could -- for national security reasons -- make a unilateral decision to kill a U.S. citizen overseas and the decision would be "judicially unreviewable."
3) Even if it is legal by the letter of the law, is it morally or politically right?