the answer is Mexico
TURKEY has numerous debates with Greece concerning the particular maritime borders, air rights, and territorial control within the Aegean Sea, is the only country (other than Greece) that borders the Aegean Sea, and is in Southwest Asia.
Mexico.
Dony
Mexico
The southwest region of the United States borders Mexico.
Texas borders just one country (besides the US), that's Mexico to the southwest.
Spain
mexico
Both Guatemala and Belize.
Ecuador borders southwest Colombia, and Panama borders northwest Colombia.
Southwest of Iraq is Saudi Arabia, which while it does border the Persian Gulf is NOT small. Kuwait is on Iraq's southeastern border and is a small country that borders the Persian Gulf.