What do you want to do about spelling errors? After all, Iran is not Iraq, so the user should probably spell it correctly to get the right answer.
Anyways you can probably rely on the end user device's own spell checking and autocorrect capabilities for that (or intelligence).
For abbreviations, just add them manually. There are only 195 countries in the world, and only a few of those have abbreviations, so it's not like your list will be inflated dramatically for adding an additional few more correct answers. Using OR conditions (among other methods, depending on how you have it set up), will allow you to have multiple valid answers per country.