Don't know where else to get help...

[Soviet Socialist Texas]

I want to create another nation, so I click CREATE A NATION, type in New Mexico... and it comes up RESERVED.

Then I search for "New Mexico" under THE WORLD. "No nations precisely matched your query." In fact, no nations showed up at all.

What the heck is going on?

[Flibbleites]

New Mexico is a nation that has ceased to exist, that's why the name isn't available and yet there's no nation with that name.

[Soviet Socialist Texas]

Okay... if it has ceased to exist, will the name ever become available again?

[A mean old man]

Speaking of which, when if at all are there going to be old names free'd up? And which old names?

[Flibbleites]

Okay... if it has ceased to exist, will the name ever become available again?

As long as it wasn't deleted for breaking the rules, possibly. Releasing old nation names for reuse is one of those ideas that's been worked on for several years.