Why did Alexander go primarily east and south from Macedonia and Greece in his conquests?

Alexander the great primarily moved east and south from Macedonia and Greece to expand his empire and spread Hellenistic culture. His campaigns aimed to conquer the Persian Empire, which lay to the east, and to establish his dominance over the region. Additionally, the east offered rich resources and trade routes, while the south, including Egypt, was strategically important for both military and economic reasons. By moving in these directions, Alexander sought to unite diverse cultures under his rule and enhance his legacy.