The US taxes the worldwide income of it's citizens. Essentially, where the money was made/invested makes no difference, other than any applicable credits for foreign taxes already paid on that income.
I am a permanent resident in the US and I pay taxes just like everyone else (income, property, sales...etc) I just don't have all the rights as American Citizens do. So I am legal, just not a citizen...
The below list is of places, normally for a combination of reason like no income tax, no property tax, no sales tax, and generally a combintaion of these that make for great retirement prospects - or...
Self-employed, any age: $400 Children and Teens classified as a dependent: $5,700 Single, under 65: $9,350 Single, over 65: $10,750 Married, filing jointly, both spouses under 65: $18,700 Married,...