The Treaty of Muhammarah (
Khorramshahr), 5 May 1922, forestalled the imminent conflict between the
United Kingdom, which held the mandate for Iraq, and the
Kingdom of Nejd, which later became Saudi Arabia after it unified with the
Kingdom of Hejaz. It was signed by
Prince Ahmed bin Abdullah on behalf of
Abdulaziz Ibn Saud, King of Najd, who did not ratify the treaty. The treaty specifically avoided defining boundaries. Following further negotiations, the
Protocol of Uqair (Uqayr), 2 December 1922, defined most of the borders between them and created the neutral zone. For unknown reasons, the treaty was not filed with the
United Nations, and nobody outside Iraq and Saudi Arabia was notified of the change nor shown maps with details of the new boundary. As the
Gulf War approached in early 1991, Iraq cancelled all international agreements with Saudi Arabia since 1968. Saudi Arabia responded by registering all previous boundary agreements negotiated with Iraq at the United Nations in June 1991. Most official maps no longer show the
rhombus-shaped neutral zone, but rather draw the boundary approximately through the centre of the territory. For example, the
United States’
Office of the Geographer regarded the area as having only an approximate boundary rather than a precise one. The Saudi Arabian–Iraqi neutral zone formerly had the
ISO 3166-1 codes NT and NTZ. These codes were discontinued in 1993. The
FIPS 10-4 code for the Saudi Arabian–Iraqi neutral zone was IY; this code was deleted in 1992. ==See also==