The chief problem is that initially, Islam was an Arabic religious, political, and demographic movement. It arose at a moment when traditional Arabic power structures were declining and the nature of global trade patterns were shifting. The emmergence of Islam occured simultanious with arabic demographic pluralities in Syria and the Levant.
But, and this is an important but, the Arabic world lacked a bread basket. Despite several extremely successful military campaigns, there were simply not enough Arabs to overcome the numbers and political strength simultaneously overcome both the Romans and Persia. Even so, within a generation or two, said Arab conquerors would have been completely swamped demographically Roman/Persian agrarian peasantry.
The only way I can see Islam, at least in its initial form, gaining hegemony is if Persia and Constantinople are simultaneously weakened by some apocalyptic combination of plague, war, and political strife at the apex of Islam's rise.
But, and this is an important but, the Arabic world lacked a bread basket. Despite several extremely successful military campaigns, there were simply not enough Arabs to overcome the numbers and political strength simultaneously overcome both the Romans and Persia. Even so, within a generation or two, said Arab conquerors would have been completely swamped demographically Roman/Persian agrarian peasantry.
The only way I can see Islam, at least in its initial form, gaining hegemony is if Persia and Constantinople are simultaneously weakened by some apocalyptic combination of plague, war, and political strife at the apex of Islam's rise.