— -- When Muslim cleric Anwar al-Awlaki became the first U.S. citizen placed on the CIA's "kill or capture" list, his father sued to challenge the government's authority to kill a U.S. citizen outside a war zone. He lost.
Awlaki, who once preached at a prominent mosque in Virginia, had fled to Yemen, his ancestral homeland, and become the eloquent advocate for waging an Islamic war against the United States. U.S. authorities held him responsible for inspiring Army psychiatrist Nidal Hasan's deadly shooting spree at Fort Hood and a young Nigerian's scheme to blow up a U.S. jet at Christmas.
Early Friday, Yemeni authorities said, a U.S. airstrike killed the cleric and Samir Khan, the American editor of Inspire, al-Qaeda's English-language Web magazine, as they traveled in a desert area east of Sana'a. President Obama called the strike a "major blow" to al-Qaeda .
The strike raised prickly legal questions and provoked measured complaints as critics condemned al-Awlaki while bemoaning the killing as an assassination that flouted U.S. and international law.
In December, a federal judge dismissed the lawsuit filed on Nasser al-Awlaki's behalf by the American Civil Liberties Union (ACLU) and the Center for Constitutional Rights. It had argued that targeted killings violate the Constituion and international law because they allow the government to execute its own citizens without judicial process.
"The government's authority to use lethal force against its own citizens should be limited to circumstances in which the threat to life is concrete, specific and imminent," ACLU deputy legal director Jameel Jaffer said. "It is a mistake to invest the president — any president — with the unreviewable power to kill any American whom he deems to present a threat to the country."
Republican presidential candidate Ron Paul, campaigning in New Hampshire, said U.S. leaders must think hard about "assassinating American citizens without charges" — even those with strong ties to terrorism.
Muslim groups around the world condemned al-Awlaki's violent message but questioned the military strike.
Dar Al-Hijrah, the mosque in Falls Church, Va., where al-Awlaki preached in 2001 and 2002, blamed its former cleric's turn toward violence on his treatment in a Yemeni prison and said in a statement that it rejects the "extra-judicial assassination of any human being and especially an American citizen, which includes al-Awlaki."
Mosque leaders "are concerned that the alleged drone attack sends the wrong message to law-abiding people around the world," the statement said.
The Ramadhan Foundation, a British Muslim group, suggested al-Awlaki should have been tried in an international court.
"One of the greatest values of our countries is that every human being is entitled to a free and fair trial," said Mohammed Shafiq, who leads the Manchester-based group. "Terrorists and extremists are no different."
The U.S. is disregarding human rights when it confronts terrorism, Shafiq said.
"I am disappointed that the United States government has increased this sort of extra-judicial killing without referring to the legal system," he said. "These drone attacks have no legal justification in international law and have killed thousands of innocent people, including children."
It is "time for the Obama administration to restore justice and the rule of law," he said.
The federal judge who dismissed al-Awlaki's case in December said the court did not have the authority to override a political decision made by the executive branch involved in an armed conflict.
The court "concluded that even though he happens to be a U.S. citizen, he can still be treated like any other belligerent," said retired Air Force Maj. Gen. Charlie Dunlap, a former Air Force lawyer who is director of Duke University's Center on Law, Ethics and National Security.
"If he wanted judicial due process, the court said he would have to surrender himself to U.S. authorities," Dunlap said.
Former U.S. representative Jane Harman, D-Calif., who served as ranking member of the House Intelligence Committee, called the strike "an intelligence and counterterrorism success."
"I think this is huge. I've been calling Yemen 'ground zero' for a long time, and this guy is the bull's eye in ground zero," Harman said. "I don't think there's anybody with dirtier hands out there."
If the U.S. or its allies used a drone to kill al-Awlaki, Harman considers it an appropriate use. The U.S. government has not acknowledged using a drone to kill al-Awlaki.
"I think drone strikes have to be used cautiously and carefully," she said. "In this case, it was."