Iraq touches the Persian Gulf at its most northwesterly.
They produce oil.
Iran is on the northwest edge of the Persian Gulf.
The most famous gulf is the persian gulf
The persian gulf
The Persian Gulf supplies most of the US's oil needs.
Kuwait was invaded by Iraq, and now remains an independent country.
Samosa originated in the Middle East, most likely in the Persian Gulf area.
Most of the Persian Gulf area is NOT democratically ruled.
The most recent war in the Persian Gulf was the Iraq War of 2003-2011.
It depends on how the question is read. If the question is asking what countries have coastlines on their north that sit on the Persian Gulf, this would include: Oman, UAE, Saudi Arabia, Qatar, and Bahrain. If the question is asking where the northern coastline of the Persian Gulf is, most of that touches Iran, with some carry-over to Iraq.
All of the Gulf countries are "oil rich" -Possibly Saudi Arabia most.