Looking at Iraq today we can see the reasoning and the much better way of Conquest Alexanders was. Indeed he battled and won these territories but basically left things as they were with a Macedonian Garrison for reasons of preserving his supply routes etc. But basically kept the status Quo to appease the people there. Or if indeed the people asked for change he would at best try to accomadate. Alexanders Empire although Initiated by conquest was cleverly based on apeasment. If he didnt placate then with such Stretched Macedonian manpower and money his expedition would grind to a halt.
The thing Conquerers and invaders get wrong is the follow up to war and battle. Which is what the Allies in Iraq are now learning. They won quick but have no Idea what to do now. Theere would be 2 answers for Iraq. One a Satrapal provinves for the Muslim Denominations to have there own pieces of land. Or second and more severe and brutal Roman Idea subjugate by total fear and terror. Not that fear would work against topdays fundamentalism..
As great as Alexander was even he wouldnt solve this mess. Iraq Is a modern day Alexander Afghanistan.and Alexander knew he couldnt keep wiping out the Eastern Peoples with terror tactics and got the hell out of there throwing the ball to Porus.
Alexander was astute enough with Persia not to ruffle feathers or causing agravation for himself.. As the line in Gladiator Went.. Win the Crowd Alexander as a whole was all about winning the Crowd for his own personification and glory.
Kenny