(CNN) -- The death of Anwar al-Awlaki deprives al Qaeda of a leading propagandist and an inspirational figure to jihadists the world over. His calm eloquence and fluent English turned al-Awlaki into a YouTube phenomenon, and his emergence as the ideological guide of al Qaeda in the Arabian Peninsula, or AQAP, put him at the heart of one of the most dangerous terror groups on earth. Known as the "Professor" by the group's operatives, he also became the spiritual mentor to would-be jihadists living in anonymous suburbs half a world away. Al-Awlaki arrived in Yemen after spending much of his youth and adult life in the United States, where he studied in Colorado and was an imam at mosques in California and the Washington metro area. He even gave interviews in the aftermath of 9/11 decrying the terror attacks. But at some point he became disillusioned with his adopted country -- perhaps because of a series of encounters with U.S. law enforcement over his alleged use of prostitutes. When he left in 2002 he took a unique understanding with him of the vulnerabilities of an open society, the sentiments of American Muslims and the opportunities of social media in the 21st century.
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Al-Awlaki was at the heart of one of the most dangerous terror groups on earth
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Growing up and living in the United States gave him a unique understanding of U.S. society
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He mocked U.S. intelligence for not picking up his e-mail traffic with Maj. Nidal Hasan
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He had escaped at least two previous attempts to kill him
The seventh edition was published this week, edited by another @placeholder jihadist in hiding in Yemen who had been attracted to the cause by al-Awlaki's teachings.