Rich Americans get second passports, citing risk of instability (cnbc.com)
A 2nd passport can enable some to travel incognito – that is, Americans and some Europeans are not welcomed in all parts of the world – thus, dual citizenship can enable one to travel under a different flag.
Dual citizenship is also advantageous to those who work in multiple areas around the world. As I have mentioned on this blog, I know at least half a dozen former colleagues who have dual U.S./EU citizenship – which enables them to work in the U.S. or Europe, without the need for additional visa applications. Since they work in tech consulting, this makes their services highly desirable to international organizations.