The most difficult countries to obtain citizenship include Vatican City, Liechtenstein, Bhutan, Qatar, Saudi Arabia, Kuwait, Switzerland, China, and North Korea. If you have ever submitted an application for citizenship, you will know just how difficult the process can be.

The hardest citizenships to obtain are typically those of countries that do not rely on "jus soli" (birthright citizenship) and have extremely strict naturalization requirements. Vatican City is arguably the hardest, as citizenship is only granted to those who work for the Holy See and is revoked once that employment ends. Qatar and Kuwait are also notoriously difficult; in Qatar, you typically must reside in the country for 25 years, be proficient in Arabic, and have a clean record, and even then, naturalization is rare. Bhutan requires 15 to 20 years of residency and a rigorous exam on the country’s history and "Gross National Happiness" philosophy. Liechtenstein is another challenge, requiring 30 years of residency (though this can be reduced if the local community votes to approve you). Finally, North Korea is practically impossible for foreigners to join. Most of these nations also prohibit dual citizenship, meaning you would have to renounce your original nationality to join theirs, adding another layer of difficulty to the process.