I have thoughts on why it happened, but it's all speculation at this point.
There isn't enough info for me to speculate, but I am sure there is far more for you there. However, there seems to always be a "why" to justify this kind of thing and I really believe it comes down to the way we have been made to feel like we are eternal victims oppressed by someone or other.
The troops are all a political stunt. It's not like they are really needed as far as I know. It's all about you know who flexing their muscles.
It is all inflammatory to further drive a wedge.
I'm definitely the sort of person who can appreciate that sometimes crap just happens, so I don't really look for blame as much as some people do. This case is just laid out a bit too perfectly for it to be something else. Based on the comments I have seen about it, there appear to be a lot of people who believe the same thing I do.