Hello,

The tax settings screen doesn't allow any more than 200 of the 255 countries from being displayed.  It appears that they can all be added, just not displayed.

Ideally it would be far easier to allow you to "enable" countries in an entirely separate area that would simply require you to put a check next to each of the countries you want to sell to.  The Tax Settings should only be needed in order to allow you to add Tax Settings specifically and only when needed. 

-Bryan