I don't get this joke please explain kthnx
K, here the whole explenation in a nutshell:
Dat Face Soldier and his crewOr, if you prefer TF2 characters:
REMOVE POOTISOr, if you prefer tl;dr versions:
The old man constantly shown in the video is Radovan Karadzic, president of the illegitimate Bosnian Serb Republic. When the UN finally intervened and put an end to the conflict in 1995, he was charged with war crimes against humanity. After the Yugoslav Wars, Serbia (Orthodox Christians) turned its attention to recently-independent Bosnia (Muslims) where Serbs made up 32% of the population. As the Serbs gained ground they systematically murdered eventually 200,000 Muslims in methods similar to those that occurred under the Nazis during WW2 including mass shootings, forced repopulation of entire towns and confinement in makeshift concentration camps.