Why did Islam initially expand by conquest? Can you distinguish between the expansion of Arab power and the spread of Islam?

Arab power was background of the spread.

Explanation:

The Muslims conquest after the death of the Mohammed led to the occupying of the vast majority of the areas and conversion of the Islam followed and this boosted the missionary activities of the imams. With the Muslim conquest spread through the middle east and the Arabic empire expanded by the spread and had its roots in the Arabic world united under the Mohammad.