[klipt]

> It takes 6-8 years of residency to get German citizenship

That doesn't sound any slower than the US - it'll probably take me around 8 years of post-student residency to become a US citizen (3 on H1-B, then 5 on a green card - and bear in mind it's much faster for me than for someone born in India or China, who face massively backlogged green card quotas).

A lot of people fixate on citizenship, but permanent residency is 99% as good as citizenship. Ask any green card holder, they'll tell you the real challenge is getting the green card. The subsequent 5 year wait for US citizenship is gravy by comparison.

[dalke]

We're talking about expatriation. It's difficult to live as a stateless person. You really want to have citizenship in another country before giving up US citizenship.

While permanent residency might be a possible substitute, the lack of any citizenship will likely make it more difficult to travel to another country, and there may be legal problems should you have a child as a stateless mother.

[klipt]

True, assuming you're not a dual citizen to start off. Some of the Americans moving to Europe might already have a European citizenship by descent (although not necessarily of the country they end up settling in).