It wasn't too long ago that nearly every human being lived their entire lives without traveling more than 10-miles from home. For the small handful of people who actually did venture out, you could make it across the globe with no official documents whatsoever.
This began to change rapidly in the 1920s. The newly formed League of Nations began meddling in the business of international travel and worked to standardize an international identification document that would be required by travelers to cross most borders.
The ominous phrase, "Papers, please", was born from this standardization.
These days, international travel is big business for governments. Think about all the massive bureaucracies that have been created as a result of national borders: Immigration checkpoints. Customs. Border patrol. Passport offices. Even the IRS is involved in passport application procedures.
As much as it would be nice to go back to the days when people were free to criss-cross the world without such inconveniences and indignities, this just isn't going to happen. So since we can't go back to a zero passport world, the next best solution is a multiple passport world.
Let me explain.
Nearly everyone on the planet becomes a citizen of some country at birth... either due to the citizenship of their parents or the country that they were born in. Most people live their entire lives with this sole citizenship, and usually reside in the same country.
In a way, this is akin to having all of your eggs in one basket-- living, working, banking, etc. in the same country of your citizenship. And history is full of colorful examples of those baskets breaking... from economic hardship to social turmoil to natural disaster to all-out genocide.
Ultimately, the concept of having multiple citizenships is about having more baskets... and spreading your eggs around. It means having more flexibility, no longer being constrained by the limitations of a single country. For example:
1) Safety. As I'm fond of saying, nobody ever hijacks an airplane and threatens to kill all the Lithuanians. There are no evil men in caves plotting terrorist attacks against Uruguayans. Nobody is burning Panamanian flags in the streets of Pakistan to protest innocent deaths at the hands of Panama's fleet of unmanned Predator drones.
Simply put, some nationalities are a bit more high profile due to the actions of their governments. Others aren't.
2) Travel freedom. Did you know that a US or Canadian passport isn't particularly useful to travel to South America? US and Canadian citizens have to obtain a visa, in advance, just to travel to Paraguay! Or Brazil. Plus Argentina and Chile both charge 'reciprocity fees' on arrival (since the US and Canadian governments do the same thing.)
Other nationalities are welcomed with open arms. Singaporean citizens, for example, enjoy visa free (or visa on arrival) travel to nearly every country on the planet. Singapore is the only passport in the world that commands visa free (or visa on arrival) travel to the US, UK, European 'Schengen Area', China, and India.
Further, did you know that you can be barred from traveling to some Middle Eastern countries if you have an Israeli immigration stamp in your passport?
Once again, multiple passports means more options, and more freedom... in this case, the freedom to travel.
3) Business and investment freedom. If you're a US citizen, foreign banks don't want to deal with you, foreign brokers don't want to deal with you, and most foreign investors don't even want to risk getting in bed with you.
FATCA, Dodd Frank, etc. all make it too difficult for foreigners to deal with US citizens; nobody wants to risk the IRS or SEC knocking on their door. As a result, many US citizens have been kicked off the boards of foreign companies, had their foreign bank accounts closed, and been disallowed from buying into lucrative foreign IPOs.
Having another citizenship normally circumvents these hurdles.
4) 'Citizen benefits'. If national healthcare is your thing, there can be a lot of benefit in having a second citizenship-- in many cases, you'll enter the public healthcare and pension system, giving you a potential backup in case you need it.
5) Relocation and work possibilities. With a second citizenship, you'll always have the right to live and work in another country. Imagine, for example, having a European passport, entitling you to work anywhere in the EU. If you're living in the US or Canada now, that could potentially open up an entire new line of lucrative opportunities to pursue.
6) The insurance policy. Ultimately, having a second passport is like having an insurance policy. You might not ever need it... but you're going to be really glad that you have it in case you ever do.
Again, history is full of catastrophic events that have caused tremendous turmoil in nations... and people who have been trapped inside with no way out have had their lives turned upside down.
A second passport can be that ticket out... safe passage for you and your family to a new place where the opportunities are better, safer, and brighter. It's a scenario that no one can really imagine... but history shows that few people ever do.
You probably have the foresight to understand that the western world is entering another period of severe turmoil. You might even already be thinking about second citizenship. If so, consider the Dominican passport. It is the most economic quality passport on the market today. And, the process for acquiring one can be expedited to only 6 months.