During the 1990 Invasion of Kuwait, the first indication of the Iraqi ground advance was from a radar-equipped tethered balloon that detected Iraqi armor and air assets moving south. Tethered surveillance balloons were used in the 2004 American occupation of Iraq. They utilized a high-tech optics system to detect and observe enemies from miles away. They have been used to over watch foot patrols and convoys in Baghdad, Afghanistan, and are permanently installed above US military bases in Kabul and Bagram.