But do you actually lose anything?
This individual collects ss and medicare, uses US based healthcare, takes advantage of all US perks.
I don’t see that life has changed for her except that she now has British benefits too.
Perhaps not.
Lying is often beneficial. That is why people lie so often.
Loyalty is often costly. That is why so many people are disloyal.
Benedict Arnold was a kind of like a dual citizen between the US and UK, and he is universally liked and respected to this day!
Your friend should be careful that she does not get socked with UK taxes. I pay about half my income in various US taxes. If I had to pay UK taxes too, I would be in the hole every time I got a paycheck!
I believe it is a form, some documents showing ID and American citizenship and a hundred bucks or so .... She wants (she says) to do it to continue to support Duterte as President of the Philippines .... we both love him ....
So as far as I know, nothing is lost to her American status.
Just from my own perspective as I am not a dual citizen I found that when I lived overseas I had to pay for workers comp and file for taxes in the USA but was unable to use any of the bennifits as they were of course Unavailable.
Being a foreign national there were no bennifits and quite a few additional costs from the places I stayed.