Before exploring the factors contributing to the Muslim expansion, it is necessary to highlight four points related to the idea of jihad, for it is the backbone of Islamic conquests.
First, the term ‘jihad’ has a number of meanings: jihad al-da‘wah, namely, striving and bearing all sorts of potential hardships and suffering for the sake of propagating the Message of God; jihad al-nafs, which means struggling against the evil in oneself by adhering to the Lord’s commands in order to lead a virtuous life and help to change society for the better; and ‘armed jihad’, which is fighting and waging war against aggressors and oppressors. Armed jihad was legalized as self-defence shortly after the Prophet settled in Medina. It is considered an individual duty for all Muslims who are capable of fighting, in the event of being attacked by the enemy, and is a collective duty if no invasion has been launched.
Second, ‘There must be no coercion in matters of faith’ (Qur’an 2:256). This verse is regarded as a cornerstone of both the Islamic Call and jihad, for Islam sees faith as a matter of conviction. It never seeks converts by means of compulsion, threat or pressure. Instead; Islam addresses the human mind, intellect, and commonsense.
Freedom of belief is the most basic right that identifies man as a human being. To deny anyone this right is to deny him or her humanity. Freedom of belief also implies the freedom to express and propagate one’s belief without fear of threat or persecution; otherwise, that freedom is hollow and meaningless.
The genuine adoption of any faith or idea should be based on a firmly-held belief, a belief that is clearly recognized by the intellect, and entirely endorsed by the heart. It is only this adoption that Islam holds as legitimate and valid. To illustrate this fact, one may refer to the early Muslim converts in Mecca. Since declaring their new faith, they had undergone brutal torture and increasing physical and psychological pressure to renounce the Message of Islam. What made them uncompromising was, indeed, their deep and passionate attachment to their newly adopted faith. However, it has been argued that that verse (2:256) was abrogated, and the Prophet forced people of other faiths to accept Islam, and accepted no alternative but total surrender to the Islamic faith. Logically speaking, though, the verse is never susceptible to abrogation, because it pleads for the freedom of belief, expression, and opinion. So how can such a lofty principle be abrogated or repealed? On the other hand, a lot of verses in the Qur’an confirm the meaning of the verse, such as ‘Had your Lord so willed, all people on earth. Do you, then, try to compel people to believe?’ (10:99). And, ‘Say (O Muhammad): “This is the truth from your Lord. Let him who wills, believe in it, and let him who wills, reject it”’ (18:29). Elsewhere, the Qur’an says, ‘Often will those who disbelieve wish that they had been Muslims’ (15:2).
Third, some writers cite the following prophetic tradition as evidence of coercive conversion carried out by the Prophet. The Prophet is quoted as saying, ‘I have been ordered to fight against people until they testify that there is no god but Allah and that Muhammad is the messenger of Allah and until they perform the prayers and pay the zakat. If they do so they will have gained protection from me for their lives and property, unless [they do acts that are punishable] in accordance with Islam, and their reckoning will be with Allah, the Almighty.’ This tradition has two possible readings. First, lexically speaking, there is a difference between the words ‘fight’ and ‘kill’. The former (fight), which is mentioned in the tradition, necessarily involves two parties fighting each other, one in self-defence, while the other is on the offensive. By contrast, the latter (kill) does not involve this participation. In the light of the lexical meaning of the word ‘fight’, the tradition means that I have been ordered to fight those who stand as a stumbling block to fulfilment of my task of calling to the path of God. Second, the word ‘people’ in the tradition is not a generic term that includes all groups. Instead, it refers to a specific group of people (aggressors and oppressors), whom the Prophet is permitted to fight. This interpretation is backed by hard facts. Historically speaking, there is no shred of evidence that shows the Prophet compelled the Arabs to embrace Islam, and did not accept any alternative. On the contrary, the Prophet did accept al-jizya (poll tax), as an alternative, from the people of the Book and the Magians, in return for protecting them and securing their lives and property. The Prophet only fought those who had fought him, and driven him out of Mecca. When he immigrated to Medina, he drew up a document with the Jews, defining their rights and duties. Some had betrayed him and tried to assassinate him, so he expelled some of them, and killed others. Had they remained faithful, the Prophet would never have taken a firm stand against them. It would be hard to prove that the Prophet betrayed his pledge or fought his loyal non-Muslim allies.
Fourth, classical Muslim jurists debated about what would serve as sufficient cause to fight non-Muslims. Are non-Muslims to be fought because of their mere disbelief, or because they have shown acts of aggression or posed a threat to Muslims? The vast majority of jurists believe that fighting is only legitimate in case of an attack or aggression. In this context, Ibn al-Salah, a traditionist and jurist, says, ‘The basic rule [in jihad] is to spare disbelievers, because God does not will the termination of peoples, nor did he create them to be killed. However, their killing is only permitted due to temporarily existing harm, caused by them. And this [killing] is not a punishment for their disbelief, because this world is not a world of reckoning. The reckoning rather is held in the hereafter.’ This view is supported by solid evidence; the Qur’an, in several verses, orders Muslims to deal kindly and equitably with non-Muslims, unless they have shown an inclination toward violence and attack. It says: ‘And fight in the way of God those who fight you, and do not transgress limits, for God does not like the transgressors’ (2:190) and ‘God does not forbid you to deal justly and kindly with those who did not fight against you on account of religion, and did not drive you out of your home’ (60:8). Elsewhere, the Qur’an states: ‘And fight the pagans all together as they fight you all together’ (9:36). Similarly, it is reliably reported that the Prophet instructed that non-combatants (women, children, the aged, monks, and priests) are to be left alone. Only those who take up arms are to be fought. After a battle, the Prophet saw a dead woman. He was very upset, and reproached his army for killing a non-combatant. These traditions clearly indicate that disbelief per se is not the driving force behind jihad. Otherwise, the Prophet would have made it lawful for Muslim troops to kill every disbeliever, whether combatant or non-combatant.