Originally Posted by Pulaski

Agree.

There are a couple of mistaken beliefs that were true in the past (quite a long time ago now) and which still seem to be fairly common,and we see mentioned on BE from time to time even today, that (i) the UK doesn't allow dual citizenship and/or that you will lose your British citizenship if you naturalize as a citizen of another country, and (ii) that the US doesn't allow dual citizenship and/or forces you to abandon your other citizenship and/or confiscate your non-US passport. The first of those hasn't been true since the late 1940's IIRC and the second was found to be not true in the late 60's or early 70's (and I don't think had ever been legislated), so while the US State Department doesn't "recommend" dual citizenship they have recognized that they are more or less powerless to do anything about it if someone is (at birth) or becomes, a dual citizen.

There are some people who think that becoming a citizen will complicate your taxes, which has an element of truth in that you will have to prepare annual tax returns, but that is true anyway for permanent residents, so unless a permanent resident gives up their PR status/ green card there is no difference from a tax perspective between being a US citizen or being a permanent resident. Leaving the US and giving up your PR status to try to extricate yourself from the clutches of the IRS is a whole other topic, and not necessarily without some merits.

Then there are people who think that becoming American somehow dilutes their Britishness.