WASHINGTON (CBS/AP) -- President Barack Obama called the death of a U.S.-born jihadist cleric - killed on Friday by a drone attack in Yemen - a "major blow" to al Qaeda in the Arabian Peninsula, and said the U.S.-directed attack provided "further proof that al Qaeda and its affiliates will find no safe haven anywhere in the world."
Anwar al-Awlaki, a leading propagandist and operational leader for Al Qaeda, and Samir Khan, an American of Pakistani heritage who edited the slick Jihadi Internet magazine Inspire, were killed in an air strike on their convoy in Yemen by a joint CIA-U.S. military operation, according to counterterrorism officials. Al-Awlaki was targeted in the killing, but Khan apparently was not targeted directly.
In remarks at Fort Myer, Va., Mr. Obama also praised the United States' successful alliance with Yemen's security forces. "Working with Yemen and our other allies and partners, we will be determined, we will be deliberate, we will be relentless, we will be resolute in our commitment to destroy terrorist networks that aim to kill Americans, and to build a world in which people everywhere can live in greater peace, prosperity and security."
In December 2010 the Guardian reported that among the secret U.S. diplomatic cables released by WikiLeaks was notice by the Yemeni president secretly offering American forces unrestricted access to Yemeni territory to wage unilateral strikes against al Qaeda targets.
Awlaki's death will deal al Qaeda in the Arabian Peninsula a serious blow, said CBS News terrorism analyst Juan Zarate - particularly his work to draw young Muslims into the jihadi mindset.
"His role as a propagandist actually will be very difficult to fill," says Zarate.
Al-Awlaki's death is the latest in a run of high-profile kills for Washington under Mr. Obama. But the killing raises questions that the death of other al Qaeda leaders, including bin Laden, did not.
Al-Awlaki is a U.S. citizen, born in New Mexico to Yemeni parents, who had not been charged with any crime. Civil liberties groups have questioned the government's authority to kill an American without trial.
Al-Awlaki played a "significant operational role" in plotting and inspiring attacks on the United States, U.S. officials said Friday.
Khan, who was from North Carolina, wasn't considered operational but had published seven issues of the jihadist online magazine, offering advice on how to make bombs and the use of weapons.
Seeking to justify the targeted killing of a U.S. citizen, President Obama outlined al-Awlaki's involvement in planning and directing attempts to murder Americans.
"He directed the failed attempt to blow up an airplane on Christmas Day in 2009. He directed the failed attempt to blow up U.S. cargo planes in 2010," Mr. Obama said. "And he repeatedly called on individuals in the United States and around the globe to kill innocent men, women and children to advance a murderous agenda."
U.S. officials have also said they believe al-Awlaki inspired the actions of Army psychiatrist Maj. Nidal Hasan, who is charged with 13 counts of premeditated murder and 32 counts of attempted premeditated murder in the attack at Fort Hood, Texas.
In New York, the Pakistani-American man who pleaded guilty to the May 2010 Times Square car bombing attempt said he was "inspired" by al-Awlaki after making contact over the Internet.
Jameel Jaffer, deputy legal director of the American Civil Liberties Union, condemned the drone attack on Awlaki, saying, "The targeted killing program violates both U.S. and international law.
"As we've seen today, this is a program under which American citizens far from any battlefield can be executed by their own government without judicial process, and on the basis of standards and evidence that are kept secret not just from the public but from the courts," Jaffer said. "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. 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."