Unfortunately it's not true, the video cannot simply be dismissed as an act of misplaced bravado by a few rogue soldiers. Rather it is a symptom of the kind of psychosis that comes along with the long-term occupation of a land and its people. The United States is ten years into its Afghan mission. We went to Afghanistan to avenge the barbaric acts of 9/11; we were indoctrinated to think that this land hosted individuals with no regard for human life, who would happily kill innocent men, women and children to further their own twisted view of religion. Al-Qaeda became conflated with the Taliban, who in turn, became conflated with the Afghan people. We can run all of the feel-good stories we want about American soldiers helping to open medical clinics or schools for girls in Afghanistan, but at home we continue to promote the idea that if we don't continue to fight “them” over there, terrorist acts will return to our shores, just look at some of the rhetoric from the presidential campaign that supports this very idea. For our soldiers on the ground, they are told of the need to constantly be on guard, that any Afghani they meet could be one of “them”.
The surprise then shouldn't be that a group of US Marines decided to dehumanize a group of enemies they had killed, the surprise should be that this sort of thing doesn't happen more often since it is the natural progression of any long-term occupation – the trend, perhaps the psychological need, to dehumanize those you are occupying, since how could you control every facet of someone else's life, down to their very right to have life at all, if you consider them a human being equal to yourself? The history of the 20th century offers ample evidence to support this idea. Members of the Israeli political left and peace movements decry their nation's occupation of the Palestinian territories for this very reason, adding that Israeli soldiers' dehumanizing of the Palestinians also has a corrosive effect on Israeli society as well; one can also look at the occupations of various European nations during World War II, or Japan's brutal treatment of those in the regions of China they occupied; and, of course, there is also the entirety of Europe's Age of Colonization to consider as well.
Viewing the occupied as something less than human is a natural outgrowth of occupation as the Marine video reminds us. It should also serve as a powerful example of why it is time for the United States to end its Afghanistan mission once and for all.