The Kurds are yet another group who got shafted by Western Imperialist meddling in the Middle East. After WWI the Brits had made certain assurances to the Kurds for the establishment of an independent Kurdish nation, but ultimately reneged on these promises.
"Officially, Britain was sympathetic toward the Iraqi Kurds, but never made good on its assurances. A British memorandum written in 1930 dismissed the idea of a Kurdish homeland as 'fantastic,' adding, 'Although they admittedly possess many sterling qualities, the Kurds of Iraq are entirely lacking in those characteristics of political cohesion which are essential to self-government.'"
http://www.pbs.org/frontlineworld/stories/iraq203/crossroads01.html
Beginning in the 1920's Kurdish frustrations at displacement and disenfranchisement boiled over into riots and rebellions that were violently crushed in Turkey and Iraq. The British pioneered the use of aerial bombings of Kurdish civilian targets in Iraq.
"Phosphorus bombs, war rockets, metal crowsfeet [to maim livestock] man-killing shrapnel, liquid fire, delay-action bombs. Many of these weapons were first used in Kurdistan."
There is evidence that the RAF also used mustard gas against the Kurdish civilians.
http://www.sheffieldagainstwar.org.uk/articles/britain-reserves-the-right-to-bomb-niggers/
http://www.guardian.co.uk/comment/story/0,3604,939608,00.html