what does a.o. refer to?

I do not think i have seen this before.
could a.o. be an abreviation for a country in the region? or perhaps a company?

In order to make a guess i would suggest giving more context.
Where is the passage from?
In general, what is the original publication about?
In which country did you first read this?

No, it's not a country of the region.
As a matter of fact, ao it's the international abbreviation for Angola..

it stands for area of operation

I believe it means "among others," which would explain why only certain countries were named. This is not a standard abbreviation in English.

Upon reflection, I believe Setanta is correct.

Setanta is always correct.

Maybe it's someone trying to modernise inter alia.

Just ask him