Originally Posted by Larrey
1+2. The political development in the Middle East until the Crusades was one of political fragmentation. It created precisely a situation of city-states ruled by locally strong dynasties. The Crusades helped force political reunification. Not that it was stable. Lack of politically stable political institutions in the Islamic world might as well be presented as a factor.
Agreed. The Islamic world was always changing it's political map. That made things more difficult.
3. Egypt and Mesopotamia always had huge demographic potential. At least Egypt didn't again reach peak Roman population levels until the 20th c. The argument seems definitely circular — because they did not have a demographic take-off like the European one, they couldn't have one... QED.
Egypt and Mesopotamia had a combined demographic potential of 12 million people. Europe had 150 million people in 1750 AD.
See the difference?
4. They weren't closed off from overland trade along the Silk Road, and the Red Sea and Persian Gulf allowed access to the Indian Ocean, which for most of the period in question was for the most part a body of water ringed by states under Muslim dynasties. (The Europeans had to be inventive however, as they were relatively closed off.) Access to China and the western Pacific was no problem. Massive information exchange on matters like medicine and philosophy took place along the trade routes between China and the Mid East. That is, at least until the Portugese turned up with the two specific European technological advantages: ship-building and naval artillery.
It was not massive. The total estimated merchant shipping tonnage for the Indian ocean in the 15th century and the Early Modern period is between 50,000 tons and 100,000 tons. Equivalent to 1,000 to 2,000, 50 ton-size merchant ships.
However, the Italian city states already had 220,000 tons of merchant shipping capacity in the late 15th century. Venice alone had 3,000 merchant ships.
Overland trade was always insignificant before the invention of the railroad due to the cost of transport. You could only transport high value goods such as silk and spices in overland routes. So large scale long distance trade was limited to sea trade. And sea trade was only REALLY active during the Modern Period, thanks to European merchant fleets (which were far bigger than Asian merchant fleets, reaching the size of millions of tons in the 17th and 18th centuries) and during Classical Antiquity, where 90% of the known medieval and ancient shipwrecks are dated.