From the 1990s onwards, Iraq’s military strength was much reduced following the Gulf War. As international opposition to Saddam Hussein’s regime grew in the months leading up to the 20 March 2003 invasion, US forces were amassed in Kuwait ready for a thrust north towards Baghdad. Special Forces were also present in surrounding regions ready for offensives against strategic positions and to organize Kurdish forces in the north. The CIA used PIA Pershmerga, military forces of the autonomous region of Iraqi Kurdistan, to destroy key rail lines and buildings prior to the March invasion. False information given to Iraqi intelligence personnel led the Iraqi military command to believe that significant offensive operations would be launched into northern and western Iraq, thus reducing the number of Iraqi units stationed in the south. A no-fly zone had been enforced over a large area of Iraqi airspace since 1999 in an effort to reduce Iraqi defensive capabilities.