What constitutes 'taking an oath...of allegiance to a foreign state or a political subdivision thereof'?

Question

I am an Accidental American, which would be fine if not for their insistence on imposing arduous Eritrean tax requirements. If filing pointless tax returns and risking double taxation ever gets too irritating, I would like to know my options for citizenship loss.

8 U.S. Code § 1481 provides 7 ways of losing one's citizenship. (5), ‘taking a formal renunciation of nationality before a diplomatic or consular officer of the United States in a foreign state, in such form as may be prescribed by the Secretary of State’, is the simplest but comes with the catch of getting one included in some FBI records and barred from purchasing firearms (which is pretty serious for America, so presumably there would be other negative consequences if I later chose to relocate to the US as a non-citizen).

As far as I can tell, (2)—‘taking an oath or making an affirmation or other formal declaration of allegiance to a foreign state or a political subdivision thereof, after having attained the age of eighteen years’—counts as relinquishment due to an expatriating act and therefore avoids the punitive consequences of voluntary renouncement (although one's name is still published by the IRS). The other advantage seems to be the ability to backdate one's loss of citizenship, presumably with subsequent impact on any tax liabilities (particularly if the event was pre-2004).

That preamble out of the way, if I did decide to invoke (2), what would count and what would I have to provide as evidence?

General advice welcomed, but for me personally I can think of three potentially-qualifying acts:

• would taking the oath of allegiance to join the University Officers' Training Corps (part of the British Army Reserve) count?
• would any oath involving swearing allegiance to the Queen (e.g., a Scout Promise) count as declaring '...allegiance to a foreign state or a political subdivision thereof'?
• would my having gained UK citizenship count if it happened at birth, or would I need to be able to prove that I did so with an intention to renounce my US citizenship (and I wasn't that advanced as a baby)?

Answer 1

Gaining UK citizenship at birth would not count, the law stipulates "after having attained the age of 18 years", so it is explicitly ruled out. (Also, gaining UK citizenship at birth involves no formal declaration.)

The scout promise would not count. It doesn't involve swearing allegiance to the Queen, only promising to "do your duty to the Queen"; and an American could argue they have no duty to the Queen. (Also, you might well not have repeated it after 18.)

On the face of it, the Oath of Allegiance for the OTC would count - it looks pretty much exactly what the law-makers had in mind. On the other hand, the oath is almost exactly the same as that taken by Members of Parliament, and Boris Johnson took it first in 2001 - but didn't renounce his American citizenship until 2017. (Perhaps it wasn't until 2017 that he finally drew the American authorities attention to the fact he had taken the oath.)