I have a feeling that it may not be authentic Annie. In 25 pages of Google images, I have only seen it on one personal website and as a poster image (including with a 2007 copyright tag). I stand to be corrected however. Phil
It is an authentic poster. I'm unsure of the actual artist (i don't think it's Leet), but it was originally published in 1915.
It took me by surprise because I'd never seen it before .... but I bet you're right Phil !! ( Then I thought I'd better ask !! )
I think I've found the source of the poster here: http://images.google.co.uk/imgres?imgurl=http://www.firstworldwar.com/photos/graphics/gws_kitchener_01.jpg&imgrefurl=http://www.firstworldwar.com/photos/commanders5.htm&usg=__VMI1kv_i15CBN6bX5N5fRYYh_Aw=&h=3375&w=1600&sz=294&hl=en&start=8&um=1&tbnid=kgPxEhx6xni4EM:&tbnh=150&tbnw=71&prev=/images%3Fq%3Dlord%2Bkitchener%2Bportrait%26um%3D1%26hl%3Den%26sa%3DG The source, GWS, is given as: From there on in I'd say artistic licence.