Why did the western government allowed germany to conduct the holocaust

They did not, the western allies did not know about the holocaust until after they conquered Germany and they immediately freed all the Jews from the concentration camps.

the iconic cartoon that you are talking about is probably a man standing on top of a country with his legs spread wide. 

this cartoon suggests that europeans are powerful enough to subdue an entire continent. this was a satirical image that was drawn during the time of the colonization of the british empire in africa.

this image was inspired by the plans of the british empire to create telegraph lines all over africa promoting the further spread of its colonies through faster communication. the picture depicts the colonial mentality of the british empire in general as well as the struggle of africans to claim their own land. hope this ! (: