I dont know about the acadamies, but from what i have read about Rotoc, sometimes you have to renounce it and sometimes you dont. What they ask is if you are willing to renouce the other nation with the answer being yes. Many times, there are no need to follow through. Just like bopper mentioned above that Ethan is a dual US/Canadian citizen, I have a feeling the US isnt too worried about US/Canadians or US/UK. My son is US born with a dual citizenship with Israel. My son renouncesd his Israeli citiznenship and although Israel has been taken off the US blacklist recently, i have a feeling they still dont look kindly at US/Israeli citizens. There was an incident where an older US dentist decided to close his practice and join the Navy as a dentist. He was denied security clearnence and the ablity to join because his mother who had Alzheimers and dementia lived in Israel. They were concerned because he called his mother regularly. The Navy wound up revering their decision after pressure was put on them
I am guessing the Navy told the sailors to keep their mouth shut when going into for their dental exam