Henry B. Gonzalez, speaking in the United States House of Representatives on March 24, 1992 said that Britain used gas against the Kurds, and has often been quoted since; however, a question remains over how well informed Mr Gonzalez was.
Another historian, Lawrence James, says "By September the local commander, General Sir Aylmer Haldane, was beginning to get the upper hand, although he was still desperate enough to clamour for large supplies of poison gas. It was not needed, for air power had given his forces the edge whenever the going got tough.. On whether gas was used he writes that: "RAF Officers asked Churchill... for use of poison gas. He agreed but it was not used
Niall Ferguson, in his recent book, The War of the World writes: "To end the Iraqi Insurgency of 1920…the British relied on a combination of aerial bombardment and punitive village burning expeditions. Indeed, they even contemplated using mustard gas too, though supplies proved unavailable”.
Anthony Clayton, writing in the Oxford History of the British Empire: vol. four: The Twentieth Century that "[T]he use of poisonous gas was never sanctioned
In the 1920s there was a general idea, which Britain shared, that the rules of war applied to only conflict "between civilized nations." It had earlier been stated clearly that "they do not apply in wars with uncivilized States and tribes" in the Manual of Military Law of 1914.
In a War Office minute of 12 May 1919, Winston Churchill argued for the use of tear gas: "I do not understand this squeamishness about the use of gas. We have definitely adopted the position at the Peace Conference of arguing in favour of the retention of gas as a permanent method of warfare. It is sheer affectation to lacerate a man with the poisonous fragment of a bursting shell and to boggle at making his eyes water by means of lachrymatory gas. I am strongly in favour of using poisoned gas against uncivilised tribes. The moral effect should be so good that the loss of life should be reduced to a minimum. It is not necessary to use only the most deadly gasses: gasses can be used which cause great inconvenience and would spread a lively terror and yet would leave no serious permanent effects on most of those affected.
It should be noted that Churchill refers to tear gas as poisonous; in the vocabulary of the time, "poison gas" may not have referred to lethal agents, as it does today.