When you plan attacks against your own country - does citizenship prevent you from being targeted and killed. No - A threat is a threat.
He was a threat - Past tense intended.
Targeted killings: Traitors like al-Awlaki deserve what they get | Full Comment | National Post
The poster child for this debate is Anwar al-Awlaki, an American-born al-Qaeda recruiter who was linked to several attempted, but failed, attacks against the U.S. homeland. In 2011, an American drone hunted down al-Awlaki and his entourage in Yemen, and wiped them out with a missile. This led to much controversy, particularly among civil libertarians, who argued that al-Awklaki had been executed by his government without due process of law, including a fair trial and appeals process.
This argument does not hold up to scrutiny, however. Al-Awlaki was not a prisoner facing trial, he was an enemy soldier killed in a military operation. It is true that he was specifically sought out and targeted for that mission, but high-value leadership targets have always been fair-game in war, and through his actions, al-Awlaki had made himself a very high-value target indeed. Fluent in English and technologically savvy, the so-called “YouTube bin Laden” had proven a potent propagandist, spreading al-Qaeda’s message and recruiting among disaffected Westerners, ripe for conversion into home-grown al-Qaeda fanatics. al-Awlaki was not simply another al-Qaeda insurgent or Taliban rifleman, but a potent weapon in their arsenal, and as a member of al-Qaeda in the Arabian Peninsula, was a direct military threat to the pro-Western government of Yemen.
All of this would have been true regardless of his citizenship. It was al-Awlaki’s actions, not his place of birth, that required a firm response. It should also be noted that the U.S. is not specifically seeking out and eliminating every American citizen that allies with states or organizations hostile to American interests. Only those who are high-value targets on their own merits are specifically sought out and eliminated with these drone strikes, as is entirely appropriate. If the U.S. was seeking out every traitorous citizen, there would be a stronger legal argument to be made for calling such actions extrajudicial executions. Given that al-Awlaki was a willing member of an enemy military unit engaged in acts of war against America and its allies, his death is more properly viewed as a battle casualty incurred during a successful operation.
Throughout history, there have been turncoats and traitors who have sided against their country by fighting alongside its enemies. When taken alive, they have sometimes been dealt with harshly, absent of any judicial oversight. That is not necessary in our modern era. But nor should the U.S. military holds its fire when an enemy leader is in its sights, because a member of their party, or perhaps the leader itself, happens to have been born American. American citizenship must not become a shield for those who wage war on America to hide behind.