In 1990 Iraq invaded and annexed Kuwait, precipitating the Gulf War by which Kuwait's sovereignty was restored.[9][10] In July 1992 the matter of border demarcation was referred to the United Nations, which accurately mapped the boundary and then demarcated it on the ground, following the 1932 line with some small adjustments.[3] The border was accepted by Kuwait but not Iraq.[5] The United Nations Iraq–Kuwait Observation Mission monitored the border during the period 1991-2003.