This is correct. One cause of the confusion on these issues is that few people understand what US policy is: the US does not "recognize" dual citizenship. That is different from disallowing it and it does not require renunciation. Dual citizenship simply cannot be used for any purpose by an American citizen- to avoid taxes, to not register for the draft, etc.

Renunciation of the foreign citizenship MAY, however, be required in order to obtain certain security clearances for employment in sensitive positions. It may also be required in order to be hired locally at US facilities (e.g., embassies) overseas.

At the risk of being pilloried for replying to a post that is nearly seven years old (although I am not the first one to do so!), that depends on the law of the country concerned. Yes, people born in the USA are automatically US citizens except in certain cases (e.g. where the parents are in the USA as foreign diplomats), but that is not the situation in all countries. It is still in a few other countries (e.g. Canada).

Other countries that used to have a fully jus soli system (i.e. citizenship as a birthright based on birth within the territory) have now modified it (e.g. in the UK and Australia it applies only to people born in the territory who have a parent who is either a citizen or a permanent resident).

And yet other countries have never had a system anything like that, but rather have citizenship laws based on jus sanguinis, whereby citizenship at birth is determined not by place of birth but by one's ancestry.

Many countries (including the USA) now have systems that incorporate parts of each of these two systems.

Moreover, some countries have provisions that place various restrictions on those who also have another citizenship...

Many national authorities do not when it comes to issuing passports - no matter what the passport says. They will ask for proof on what basis the passport was issued (e.g. citizenship or otherwise) - which typically could be a statement from the issuing authority (e.g. an embassy) or birth certificate.

This is a pretty common issue actually when renewing passports for some nationalities as many countries (especially in Europe) try to discourage dual (or multiple) citizenship while their laws allow it.

Besides there are travel documents they aren't tied to citizenship at all - laissez passers, diplomatic passports, even travel documents for stateless individuals.

Actually, when you think about it, almost no country recognises dual citizenship. When you're in its borders (and sometimes outside of them), you're a citizen of that country and none other.

This is the same in many countries round the world; see above: almost every country recognises you as a citizen of that country regardless of other citizenships.

The US tax issue is especially vexing for those of us dual-nationals living overseas. Thankfully I pay more in tax in the UK then I ever would in the US so it's not an issue, but still...

I have a good US-born friend who worked for the US State Department. Her parents are from a Middle-Eastern country and she's a citizen of that country by default as well. She's never renounced it and the State Dept didn't like it and made her promise not to use that country's citizenship whilst under their employ. I could never work for the State Dept as I've been naturalised elsewhere. Ah well.

I don't think that last part is accurate. You could work in certain positions without a clearance (admittedly few) or you could renounce wherever you have been naturalized. Since, 9/11, the issue of dual citizenship has been a sensitive one. Normally, it comes down to the position and level of clearance. In some cases, renunciation is an absolute requirement.

I already said, in an earlier post, that most countries require proof of citizenship - such as birth certificate, naturalisation papers etc - before they will issue (or sometimes before they will renew) a passport. But once that passport is issued, if it states citizenship, it can be used to prove citizenship.

However, I was not talking about renewing a passport, but about travelling with one and, when travelling, no further proof of citizenship is required.

Please enlighten me as to which countries will then ask me for additional proof of my citizenship. I've been to over 50 countries so far, and have never yet been asked for any proof apart from my passport. International travellers are not required to carry such documents - the passport is considered proof of citizenship.

Your third paragraph is irrelevant to what I said. I was talking about a regular passport, not those issued for special purposes, such as you listed.

You are right on that count - though there are persons with passports of countries they are not a citizen off - I know several. My point was that the issuing authority will sometimes not accept a passport as proof of citizenship - as it is technically considered a travel document.

I just posted this as a general FYI/trivia - not to prove or disprove your point.

I suppose you're right - I don't know which positions at the State Dept dual-nationality is permitted for, but I know that if you've been naturalised elsewhere then you're not permitted to work in overseas postings and consular services. Frankly, I'd rather keep both US & UK citizenships than work for the State Dept anyway so that's that question answered. ;)

Understood on all counts.

To be a little picky though (in case someone IS interested), being naturalized "elsewhere" is not an absolute bar- one can renounce whatever one obtained "elsewhere" and become eligible again.

Dual nationality is rarely permitted anymore for almost any position- especially where it is exercised as opposed to having it as an accident of birth with no attempt to use it.

Interesting statistic
 

Dutch newspapers recently reported that the Netherlands (16.5 million inhabitants) has 1.1 million people with passports from two different countries, 15,750 with passports from 3 different countries and 141 with passports from 4 different countries.

I have a colleague from Mali who was naturalised as a British citizen and who lives in Amsterdam with his Spanish wife.

Both of his sons have three passports - none of them Dutch.

I have two nationalities and passports by birth - USA & Canada - one parent from each country.

As a very frequent traveller, having two passports is a major advantage. Ability to apply for a visa from two different embassies at once (especially important with those countries that take a long time to process applications) and ability to choose nationality with lowest visa fees, IE the cost for a Brazilian Visa for a Canadian is less than 50% the USA citizen fee.

As for names, I always wondered if it would be legal for me to have one name in one country and another in the other. I doubt I would change my name, but would it be legal?

Having multiple valid passports (and citizenships in some cases) can be quite useful. In countries with good (NB:keyword) nationalized health care it's often worth a trip to get a second opinion and often times cheap but quality treatment.

Secondary benefits would be avoiding certain visa fees and trip duration limitations.

You may find that, depending on the country, the nationalized health care may or may not cover you if done like you suggest. You usually need to show a permanent resident status in the country before they will give you cheap/free nationalized care. Emergency care may be free to anyone in most of these countries. Second opinions and non-urgent care is not for non-residents. There is a difference between residence and the ability to have the passport.

The visa cost is a definite plus. Mr MMP has dual citizenship. When he went to Rio he used the UK passport to enter. Much faster and easier than using his US one.

True. I didn't want to dig too deep into the details which differs for each country. This is why I said it "can" be useful. The example which popped into my mind upon writing was Taiwan. There are some additional paperwork to go through aside from just having a passport and citizenship.