As part of my effort to expand my all too limited knowledge about the countries surrounding Soviet Central Asia I have been reading about the history of Afghanistan recently. Geographically Afghanistan has served as a buffer state for much of modern history. Hence it has been easier to say where it was between rather than where it was. It is between Central Asia, the Middle East and South Asia. However, not many institutions group these areas together. Usually they are considered separate regions and separate departments will exist to deal with each of these geographic divisions. Where they put Afghanistan is up to each individual institution and there is no standardized classification. At the University of Arizona, Afghanistan is considered part of the Middle East. At SOAS Afghanistan is variously considered either part of Central Asia or part of South Asia depending upon the time period. The Centre of Contemporary Central Asia and the Caucasus calls it a neighboring region in its official pamphlet, but has sponsored a lot of events on the situation in Afghanistan since 2001. In contrast Dr. Akiner's Central Asia: History, Politics and Religion MA course did not cover Afghanistan. Hence in modern times it appears that Afghanistan has been moving from South Asia into Central Asia as far as SOAS is concerned.
Historically, I think Afghanistan's connections with India both under the Mughals and later the British makes it a closer fit for the South Asian category than either Central Asia or the Middle East. Almost equally as important, its independence from the Russian Empire and later the Soviet Union excludes it from the shared modern history of the core countries of Central Asia. Placing it in the Middle East is even more problematic. Afghanistan's historical ties to the Middle East are mostly with Iran. A country that is itself outside the Arab core of what most Middle Eastern studies departments concentrate upon. I believe a good case could be made to group Iran, Afghanistan and Tajikistan together as a unit of study on the basis of a shared Persian heritage. There are no institutions, however, that I know of that do this. More importantly I think Afghanistan shows the problems with the current geographic divisions of study. In reality Afghanistan is Central Asian, South Asian and Middle Eastern to various degrees. It can not be completely characterized as being part of only one of these regions. While perhaps an extreme case, Afghanistan is not the only country in the world that defies the current geographical divisions that academia has imposed upon the world.