I won't comment on the politcal nature of the video, there's plenty of websites out there for politcal discussion and this isn't one. However, although I assume you intended to convey a political message, the 'actual' message of the video was somewhat lost. As Mark suggests,
Adam Hart-Davis is perhaps a master of explaining how our ancestors shaped the world in which we live. Perhaps it would have been more informative to explain the Arabic influence on the development of, for example, medicine. Unfortunately this can't be demonstrated by means of a purely 'visual' medium, and your resultant video ends up being an exercise in manipulating borrowed images. There's no doubting that the visuals and audio have an impact, but is it really what you wanted?
There's nothing wrong with using other people's footage; it's a great way of understanding the interaction between audio and visual, and just as importantly how to combine subtle cuts with those designed to create impact. However, you must bear in mind that editing 'pre-edited' footage is rather like preparing a ready meal. Sure, you 'edited' the footage, but the hard work was already done!
I understand that it would have been difficult to obtain your own footage, and not many of us have the talent to create our own soundtrack, but that's not to say that you can't add more of your own, personal, touch to the video. As it stands, it looks very much like yet another 'fan' video. I've seen a fair few similar videos of football and video games for example.
I can well imagine that your peers are wowed by your efforts. Indeed, I don't doubt that you spent a considerable amount of time putting the video together. But as others on our forums have suggested, the video falls short of providing a politcal message and is typical of the plethora of 'fan' videos on You Tube.
You clearly want to create a video with a message. If that is so, I would suggest concentrating on educating the viewer.