Hi,
Thanks for your nice feedback. I just have tow questions regarding the edit:
1- Do we say as source or as a source in the below paragraph? 

For centuries, the Middle East has been the place that empires and world powers competed to control, for geographic, strategic and political reasons as source of fossil fuel and the presence of the Israeli state stability

2- Is the word "exist" correct grammatically in the below sentence? For some reason the Word Doc is not happy about some grammar, and I know it's now always correct, but wanted to make sure. 
The same Middle East the United States is dealing with now may not be exist in the next five years.
Thank a lot.
Miaad