The Tigris–Euphrates Basin is shared between Turkey, Syria, Iraq, Iran, and Kuwait.[1][2][3][4][5] Many Tigris tributaries originate in Iran and a Tigris–Euphrates confluence forms part of the Iraq-Kuwait border.[8] Since the 1960s and in the 1970s, when Turkey began the GAP project in earnest, water disputes have regularly occurred in addition to the associated dam's effects on the environment. In addition, Syrian and Iranian dam construction has also contributed to political tension within the basin, particularly during drought.