In the early period of Islam, we find that the Islamic rule was extended by the Companions (rta) of the Prophet (sws) to a large part of the world. They conquered Persia, Rome, Egypt and many other countries of their times. My question is that why did they impose Islam on these countries? Why were they not given the option of accepting Islam if they wanted to?
Indeed, it is generally held that the rise of Islam in the early period was due to a wave of 'Arab Imperialism' that shook the super powers of those times and forced them into submission. In an astounding series of conquests, country after country fell to the sword of Islam. It was not long before the Muslim empire stretched from the shores of the Mediterranean in the west to as far as Indonesia in the east.14
The fact that all these conquests took place is established history and hence cannot be denied in any way. However, the thesis that it was 'Arab Imperialism' that accounted for these conquests is something which cannot be condoned. While looking at the spread of Islam in the early period, one must resort to the basis which the Qur'an itself offers for these conquests:
It has been explained by Ghāmidī15 that those who are Divinely invested with the status of shuhadā 'ala al-nās (witnesses to the truth before people) are "used" and "employed" by the Almighty to punish people who deny the truth in spite of being convinced about it. According to the Qur'an, Muhammad (sws) and his nation were invested with this status.
Consequently, the conquest of the followers of the Prophet (sws) at that time were not basically aimed at spreading Islam as such. Their basic objective was to subjugate and punish people who had deliberately denied Muhammad (sws). Moreover, Muhammad (sws) himself initiated their task by writing letters to eight heads of state and thereby demarcated the areas where the Companions (rta) could go.
Summing up, it can be said that it is erroneous to conclude that Islam was spread by the sword. The whole exercise of the Companions (rta) was a continuation of the mission of Muhammad (sws) and no independent endeavour. This mission is governed by a specific practice of the Almighty according to which He punishes people who deny the truth even though they are fully convinced about it.
14. For a detailed account of these conquests see: Balādhurī, Futūh al-Buldān, Qum, Manshūrāt al-Arummiyyah, 1404 AH.
15. See the main article: "The Islamic Shari'ah of Jihad".