What modern country includes the ancient region of Mesopotamia?

meso, is related to middle. it means between river, the Euphrates and Tigres.

"regions along the ... Iran-Iraq borders" ... that implies that Iran is also a correct answer. Unfair!

The first discovery of writing in the Tale of Gilgamesh. Also, according to ancient astronaut theorists, the Annunaki- alien God like beings whose aspect was part animal, bestowed upon the Mesopotamians, agriculture, science, mathematics, cuneiform writing, astronomy and even language. Perhaps one view is that humankind were just self important primates who were incapable of an evolving civilization and culture. I do not share this view.

oh things are not too well in this country now.

So both Iran and Iraq then according to your description