Dual Citizen Applying For TS After Working in Embassy of 2nd Country of Citizenship

Hello,

I am a dual US-UK citizen and have been selected as a 2020 Presidential Management Fellowship finalist. As such, I am applying for State Dept and DoD positions that will require at least Secret and possibly TS clearance. Thankfully, I have done 3 internships with the State Dept (most recently from Jan-March 2018) and have been awarded Secret Clearance each time.

My question is the following: As the PMF opportunity is not a guarantee and I may have a long wait for a TS, I have recently been applying for other positions as well, one of which is a local staff position at the British Embassy to South Korea (I am a resident of Seoul). Though I have British citizenship and an expired (never used) British passport, I have applied and interviewed for the local staff position at the British embassy as an American citizen.

I would very much like to accept the position if offered but am afraid that working at the British embassy would place future clearance in major doubt or rule me out entirely. As I would be working there as an locally-employed American citizen and have not got an active British passport, nor have ever traveled on a British passport, I am hoping that my previous secret clearances and demonstrated commitment to the US through previous service would be convincing to a US investigator. If working at the British Embassy will rule me out from future clearance for certain, I will turn the job down. However, if there is a chance that it will just slow the clearance process and not be a massive issue, then I would like to risk it and accept the position.

I would be very appreciative if someone in this community is aware of the rules relating to this issue and could provide some guidance. Thank you in advance!