“The armed forces prevent dual citizens from serving due to their questionable allegiance. They too must have sole allegiance to the United States.”
But they allow non-citizens to enlist?
“Enlistment into the U.S. Navy, or any branch of the U.S. military, by citizens of countries other than the United States is limited to those foreign nationals who are legally residing in the United States and possess an Immigration and Naturalization Service Alien Registration Card (INS Form I-151/551 — commonly known as a “Green Card”). Applicants must be between 17 and 35; meet the mental, moral, and physical standards for enlistment; and must speak, read and write English fluently.”
http://www.navy.mil/navydata/navy_legacy_hr.asp?id=167
You are correct. I should have clarified those in authority, i.e. officers and their superiors are not allowed to be dual citizens. Those with security clearances are also not allowed to obtain them with dual citizenship.
Your post is most timely, however. Imagine green card holders enlisting from Iran and the commander in chief was also Iranian. Enlisted personnel are required in their Oaths to abide by the orders of their superiors without question, including their commander in chief. Would this not cause a conflict of interest and introduce a possible threat of a military coup?
If anyone questions this as being impossible, one should review their Civil War references, or any other nation within the past 50 years where a military coup was successfully completed.