So, when the Kurds came under Iraqi attack again, in 1991, there was good reason to fear that another genocide was in the offing (although President Bush's real motivation was defending the stability of Turkey, where the Kurds were fleeing).
In 1991, when the Kurds were under Iraqi attack, they fled to Turkey. 
mnli hypothesis: In 1991, when the Kurds were under Iraqi attack, they fled to Turkey.  premise: So, when the Kurds came under Iraqi attack again, in 1991, there was good reason to fear that another genocide was in the offing (although President Bush's real motivation was defending the stability of Turkey, where the Kurds were fleeing).