Long story short: my husband is Spanish and we just found out that he qualifies for citizenship. We thought he needed to be a permanent resident for 5 years, turns out it’s only 3 because we’re married and I’m a citizen.
Our question is this: can he maintain his Spanish citizenship if he chooses to obtain his US citizenship? And if we have kids after he becomes a US citizen, do they still have the ability to have dual citizenship with Spain?
We have differing opinions on these - I say no, he says yes. Which of us is correct?
(btw - he wrote the Spanish embassy to get the official answer, but if any dopers can help us out in the meantime, we’d appreciate it).
Completely non-definitive answer, but a step in the right direction, research-wise:
http://www.straightdope.com/mailbag/mdualcitizenship.html
And my non-cited and non-provable understanding is the US doesn’t recognize any dual citizenships. If you become a US citizen, they don’t recognize any past citizenship. But that doesn’t mean the country you’re “renouncing” will stop seeing you as their citizen. So asking the Spanish embassy how they’d view your husband is a good idea, though the US will most likely see him as a US citizen and ONLY a US citizen.
Thanks filmyak. Looks like he might be right. Drat. I’m really bad at admitting I’m wrong. 
Yes, it depends on Spain. The US doesn’t force you to actually give up your citizenship. I know this because my brother had dual citizenship until he was 18 - Korea forced him to choose one or the other, but the US didn’t care.
This site http://www.spainview.com/national.html says Spain doesn’t recognise dual citizenship, which pretty much jibes with what every other source I checked says. The Spanish Ministerio de Justicia says dual citizenship is allowed “in certain cases”, which usually means in the case of a dual-citizen minor who has reached their majority but not chosen anything yet.
So he’d have to renounce his Spanish citizenship, but the US doesn’t care if he actually does so, and the Spanish do but probably won’t check unless he re-enters Spain and shows his US passport or applies for a job or something.
I was just trying to do something similar to this but with Belgium. I was claiming Belgium citizenship through my father. The Belgium Consul told me that the Belgium government recognizes my claim and that if I went through all the steps I might be granted Belgium Citizenship and could keep my US also. That being said, I could also claim UK citizenship through place of birth, but I could NOT keep the UK one and Belgium at the same time.
FWIW A Coworker (US Cit) of my husband got a Spanish passport through his father who was Spanish. As others have said, I think it depends on Spain.
Source: http://www.spain-visas.com/Spanish-Citizenship-and-Spanish-Nationality-pag7.htm
And if the UK and Belgium don’t talk to each other who is to know if you claim citizenship of both?
And here’s a link to a column by the Perfect Master that eventually wanders into this issue (with more snark than in Bricker’s excellent piece, of course): How do I go about renouncing my U.S. citizenship?
They do. EU member states now issue a common passport (with the issuing state listed on the front and inside); the EU states share immigration info and such.
Its entirely up to the Spanish, but my guess is yes. Uncle Sam isn’t going to send a letter to the Embassy of Spain and say that your hubby is a citizen. Spain would have to have a specific law that says taking citizenship in another country would invalidate his citizenship.
From personal experience, Mrs Slug and I were under the impression that by taking US citizenship that her Russian citizenship would lapse. It didn’t. So we are probably about 24 months into the process of renouncing it. Pain in the butt.