China, Malaysia, vietnam, Uganda, Indonesia, Gambia, Thailand, India, pakistan, Bahrain, Botswana, Equitorial guinea, Bangla desh, UAE, North Korea, Kuwait, afghanistan, Taiwan, Iran, Iraq, Syria, Nigeria, Belarus, Saudi Arabia, Oman, Yemen, Egypt, Libya, Sudan North and South, Ethiopia, Somalia.
Nice crowd.
It makes sense. North of Rome? Germanic crazy people. West? The Atlantic Ocean. South? A thin border on the mediterannean hard up against one giant fucking desert. North east? Britain, the north of which was inhabited by such a crazed bunch of assholes the Romans built a fucking WALL to keep them out. When Welsh tin production peaked in 320, there was no point in hanging around. East? Palestine, Mesopotamia, Persia, India, China - you know - REAL civilisations. REAL money to be made. Not these crazy Pict or Celt peasant fuckers. Societies with cities and gold and stuff.
So, once they divided Roman around 310, it was basically like pulling the plug. The place drained pretty fast. If you had any money you got the fuck out and moved east. Roman didn't fall. It's method of acquiring resources met the law of diminishing returns. Its response was typical: increase the complexity of the society. Eventually, the centre collapses under its own weight. Tainter's book "Collapse of Copmlex Societies" spells it out pretty clearly. The rest is in the records. Rome didn't fall. It was sold out and abandoned.
Somebody ought to cross ball point pens with coat hangers so that the pens will multiply instead of disappear.