It is common to use an en-dash when we use same or opposite term such as cell–cell, Iran–Saudi Arabia, etc.
My question is: "Can we use an en-dash for Iran–Gulf?"
We all know that the Gulf is not a country.
First of all, a hyphen is not an en-dash. The basic rules are as follows (but check the links below for details):
Without context, it is not entirely clear what "Iran–Gulf" refers to. The Persian Gulf, which is also known as the Gulf of Iran?