Anwar al-Awlaki was an American citizen and never renouced his citizenship. In order to lose his citizenship, it must be shown that the U.S. citizen joined the foreign military or swore allegiance to another state “with the intention of relinquishing United States nationality”. There’s no evidence that Awlaki ever formally renounced his U.S. citizenship.
That being said I’m glad he’s dead...
You think Working to enable Murderers to fly plans into buildings killing thousands is showing ALLEGIANCE to the United States? REALLY?