Hi there,

You may be interested in a response that I gave to a similar question a few months ago: Why exactly do we call it the "Middle East"?

edit: the only thing I might add to that comment is a source article I've since come across on JSTOR called Captain Mahan, General Gordon, and the Origins of the Term 'Middle East' from a 1976 issue of Middle Eastern Studies which basically just goes into greater depth than I did, that Mahan didn't coin the term but for various reasons his article popularised it and has been attributed to him since.