I couldn’t find this anywhere online, so we did it ourselves. Here is a world map showing how long it takes to obtain citizenship in any given country. 5 years or less: GREEN. Between 5 and 10 years: RED. More than 10 years, or never, or based on unknown criteria, or depending on the mood of the case officer: BLACK.
Please comment here if we’ve got any of our colors wrong. This wasn’t merely online research, we also talked to friends & partners who reside in some of these countries. There are quite a few places out there with naturalization laws stating ‘citizenship can be applied for after XY years’, but in practice it’s just impossible.
I leave it to you to judge what this map reveals. To me, it serves as an interesting compass indicating whether foreigners are perceived solely as a necessary evil, or as a welcome addition in their respective host countries.