Transcript
A threads post saying "There has never been another nation ever that has existed much beyond 250 years. Not a single one. America's 250th year is 2025. The next 4 years are gonna be pretty interesting considering everything that's already been said." It has a reply saying "My local pub is older than your country".
Edit: swapped image link, RIP lemm.ee
Original link: https://lemm.ee/pictrs/image/b4d2f599-1922-4978-9db3-fc7832681c10.png
The oldest existing democracy is Iceland depending on how you define democracy. But that was around 930 ad and had free men participating in making laws
This part of your comment seems to be doing a lot of heavy lifting.
https://en.wikipedia.org/wiki/Iceland
And how you define nation/country. You could say the Isle of Mann, but it probably doesn't meet the definition.