But the 40-year-old Al-Awlaki, who was a U.S. citizen, was either keeping his extremism under wraps, or quickly became radicalized. He changed in only a few years from spouting mild criticism of the United States to becoming a charismatic terrorist leader targeted for assassination by U.S. forces or CIA drones.
After leaving the United States in 2002, he eventually made his way to Yemen and rose to such a level within the ranks of anti-Western Islamic extremism that terrorism experts put him a par with the infamous Osama bin Laden.
USA TODAY's Aamer Madhani recently delved into the background of Al-Awlaki, a fluent English speaker who understood the American mind as well as the American idiom and who was linked to some of al-Qaeda's most notorious terrorist attacks.
In many ways, al-Awlaki had eclipsed bin Laden even before that al-Qaeda leader was killed by U.S. forces in in Pakistan. Some dubbed al-Awlaki "bin Laden of the the Internet" because of his use of the Web to inspire and recruit followers.
While bin Laden kept a low profile, Al-Awlaki has hundreds of sermons on the Internet. Bin Laden's past statements issue threats and orders to Muslims to kill; al-Awlaki's sermons explain to potential followers why the West is evil and are pocked with references to pop culture given in disarming American English.
In one sermon that has been viewed more than 40,000 times on YouTube, al-Awlaki uses an anecdote about the late pop star Michael Jackson to make a point about the inevitability of death and to suggest jihadists should not fear dying for their faith.
In another lecture, he makes the case that the U.S. military's efforts in Bosnia and Kuwait in the 1990s were made under the false pretext of human rights, and the only just war is one fought for Islam. And how to justify the killing of American civilians?
"The American people in their entirety take part in the war, because they've elected this administration and finance this war," al-Awlaki said, alluding to Afghanistan and Iraq wars, in an al-Qaeda video posted recently online.
Al-Awlaki's life began not in a Muslim enclave but in Las Cruces, N.M., a desert town not far from the Mexico border and the White Sands Missile Range. His father had gone there in 1971 from Yemen with his wife to earn a master's degree in agricultural economics at New Mexico State University.
The family lived and worked in the United States until returning to Yemen in 1978, when al-Awlaki was 7. Al-Awlaki lived in Yemen for the next 11 years, during which time his father served as agriculture minister and as president of Sana University, and returned to the United States in 1991.
Terrorism experts say al-Awlaki's fluency in English, credentials as a cleric and his intimate familiarity with American culture allowed him to successfully recruit followers in the USA — something bin Laden has had little success doing.
The FBI had been keeping an eye on al-Awlaki for years, but he didn't become a priority until authorities connected him to Nidal Hassan, the Muslim U.S. Army officer charged with killing 13 people in November at Fort Hood in Texas. Hassan e-mailed al-Awlaki for advice several times before the attack, and al-Awlaki has praised him and called on other Muslim soldiers in the military to carry out similar attacks.
The FBI has since alleged that al-Awlaki is connected to several terrorist plots:
•Al-Awlaki met with Umar Farouk Abdulmutallab prior to the Nigerian's alleged attempt to blow up a Detroit-bound Northwest Airlines flight on Christmas Day 2009. Al-Awlaki said the attempt shows the vulnerability of the American aviation system despite billions of dollars spent to firm up security after the 9/11 attacks.
•Faisal Shahzad, a naturalized U.S. citizen from Pakistan, admitted to trying to set off a car bomb in New York City's Times Square in May and said he was inspired by al-Awlaki's online lectures.
•Zachary Adam Chesser, a 20-year-old Fairfax, Va., man, was arrested last month on charges of trying to join the Somali Islamic terrorist group al-Shabab. He said he was in touch with al-Awlaki.
•Al-Awlaki also preached to two 9/11 hijackers while serving as the chief cleric of a San Diego mosque in the 1990s, according to the 9/11 Commission Report, which said he helped some of the hijackers get money and apartments.
The Obama administration has not said whether something happened recently to prompt it in April to name al-Awlaki a specially designated global terrorist. Leon Panetta, then director of the CIA, said it was a culmination of things that led the U.S. to view him as a "terrorist who's declared war on the United States." Panetta said in a television interview in June that al-Awlaki was "trying to encourage others to attack this country."
When he returned to the U.S. in 1991, al-Awlaki studied first at Colorado State University in Fort Collins, and then spent the next 10 years in Denver, San Diego and the Northern Virginia suburbs of Washington before leaving in 2002 for London, where he preached at mosques known for radical ideologies.
Al-Awlaki returned to Yemen in 2004 and was arrested there on kidnapping charges. He was released in 2007 after 18 months in jail. Yemen's Foreign Ministry believes he has been hiding out in his father's ancestral region with a wife and children.
Al-Awlaki's father, Nasser, has pleaded with the government not to target his son. He has allowed the American Civil Liberties Union to file a lawsuit alleging that as a U.S. citizen, al-Awlaki has the right to a trial and killing him would be illegal.
"The power that the administration is claiming is essentially the power to effectively invoke the death penalty without charge, without trial," ACLU Deputy Director Jameel Jaffer said at the time.
Robert Grenier, former director the CIA's counterterrorism center, argued that al-Awlaki should get no special shield while waging war against America abroad. In the U.S., his actions would have warranted trial with constitutional protections, but overseas he was a military enemy like any other, subject to attack.
Although terrorism analysts say that al-Awlaki may not have had the capability to carry out a major attack on U.S. soil as bin Laden orchestrated with the 9/11 attacks, he might have been a greater danger.
"Osama bin Laden thought big and acted big," said Bruce Hoffman, a counterterrorism expert at Georgetown University, referring to the bombings of U.S. embassies in east Africa, the attack on the USS Cole and 9/11.
Instead, Hoffman says, Al-Awlaki seemed to purse a deliberate strategy of "death by a thousand cuts."
Grenier said al-Awlaki played the role of al-Qaeda's recruiter and motivator whose primary value to the organization was inspiring others to take up jihad and providing them with the religious justifications that many of them seek before engaging in terrorist activity.
The FBI investigated al-Awlaki in 1999 and 2000 after learning that he may have been contacted by a possible procurement agent for bin Laden, according to the 9/11 Commission Report. During that investigation, the FBI learned that al-Awlaki knew individuals from a charitable organization called the Holy Land Foundation that a Dallas jury ruled in 2008 was fundraising for Hamas, the U.S.-designated terrorist organization that controls Gaza.
The FBI later learned that he preached to two of the 9/11 hijackers —Nawaf al-Hazmi and Khalid al-Mihdhar — at the Rabat Mosque in San Diego, according to the 9/11 Commission Report. One witness who was not identified in the report recalled seeing al-Hazmi and al-Mihdhar stay in a guest room on the second floor of al-Awlaki's San Diego mosque, the report said.
The hijackers expressed respect for al-Awlaki as a religious figure and may have been close to him, the report said. Al-Hazmi later appeared at the Dar Al-Hijrah Islamic Center mosque in Falls Church, Va., where al-Awlaki served as the chief cleric in 2001, according to the 9/11 panel report.