Writing at Foreign Policy, Afshon Ostovar of the Naval Postgraduate School makes a comparison of the military forces of Iran and Saudi Arabia. He examines the strengths and weaknesses of each, and concludes a war between them would not be conclusive.
Iran has more men under arms, but no way to deliver them across the Strait of Hormuz. It also has significant ballistic missile forces and successful experience with asymmetric warfare. Iran's allies in the region are all nonstate actors representing, mostly, Shia populations nearby.
The Saudis have fewer men under arms but a much more robust military air capability. They too have no way to invade across the Strait. Generally the Saudis have more up-to-date military equipment and they too have ballistic missiles of unknown quality. By contrast, the Saudis have regional allies in the Gulf and in Jordan, and farther afield, the U.S.
