Winston Churchill was an advocate of gassing people and carpet-bombing urban centres, raising entire cities to the ground. One such city he ordered to be eradicated in 1945 just before the end of WW II as it was filled with fleeing German refugees: Dresden.
He had a strong dislike for whomsoever stood in his way when drawing borders: he redrew the German borders in 1944, even surprising Stalin, and made sure that these borders became ethnically effective by 1945; and he dew up borders in the Middle East in 1919.
Here, some tribes somehow got in his way, in their own homeland, and somehow needed dealing with. And Churchill dealt with them:
Winston S. Churchill: departmental minute (Churchill papers: 16/16) 12 May 1919 War Office
"I do not understand this squeamishness about the use of 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."
http://www.informationclearinghouse.info/article999.htm
Hopefully we won't be seeing Winston Churchill on any new £5 note.