The “Middle East” has been an unstable western construction for over a century. The @UNC illustrated what the US, UK, int orgs, and scholarship designated as the Middle East, Near East, western Asia, eastern Med, Arab world, etc. Thread of maps (by categories & chronological): 
US government usage
US government usage (part 2)
British usage
British usage (part 2, and also its official usage).
The usage by the UN and other International Organizations (part one)
The usage by the UN and other International Organizations (part two)
The usage by the UN and other International Organizations, here is WHO and the World Bank (part three).
Scholarly (US) usage
For a scholarly treatment of changing definitions of the Middle East, see Osamah F. Khalil, “The Crossroads of the World: U.S. and British Foreign Policy Doctrines and the Construct of the Middle East, 1902-2007,” Diplomatic History, Vol. 38, No. 2, pp. 299-344, February 2014.
Source: mideast.unc.edu/where/
