[alasdair_]

>Not really. If a wealth tax is implemented, you'll be amazed at how soon everyone moves their wealth outside of the US. You'd be very hard pressed to tax wealth outside the US.

Taxing income outside the USA already happens. Taxing wealth would also happen.

There has been a huge push in the last decade to tighten up "anti-money laundering" (but usually anti-tax) laws. The cliche of the swiss bank account offering secrecy for Americans no longer exists - the Swiss now report holdings directly to the US and similar locales do likewise.