Some say, Islam is a religion of war. Is it so?

Although war is not something desirable, humanity has not been able to get rid of it throughout history. The Quran quotes the struggle of two brothers. One of them is aggressor and the other is innocent. The aggressor one kills the innocent brother. (See Al-Maidah Surah, 27:31) The name of the innocent brother is Abel, and the name of the aggressor brother is Cain.

For the first time, human blood was shed when Cain killed his brother. As the time went on, the bloodshed in the world increased and covered everywhere. Abel and Cain are the representatives of innocence and aggression. As long as there are ones like Cain in the world, the ones like Abel will have their right of defense.

Islam permits war in certain circumstances in order to prevent the tyranny of oppressors and to maintain the universal peace. Let us have a look at this verse:

To those against whom war is made, permission is given (to fight), because they are wronged; and verily, Allah is Most Powerful for their aid. (Al-Hajj Surah, 22:39)

The ones this verse first speaks to are the Prophet Muhammad (PBUH) and his companions, who were the first-comers to Islam. While in Mecca, they were subjected to oppression, even to the torments that resulted in deaths. Some of them went to Abyssinia on the Prophets (PBUH) advice. The rest immigrated to Medina afterwards. Yet they were restless there too. On every single day, it was rumored that Meccans were about to attack them. While still in that plight, they were permitted to fight.

In another verse with regard to war, it reads as follows:
Fight in the cause of Allah those who fight you, but do not transgress limits; for Allah does not love not transgressors. (Al-Baqarah Surah, 2:190)

The verse draws our attention to several points.

1. Fight those who fight you. In other words, do not fight those who do not fight you. The Prophet Muhammad (PBUH) firmly warned his commanders not to kill women, children, and the old, those who worship in the places of worship.

2. The war in question must be in the cause of Allah (SWT). The others may fight to conquer new lands, to obtain the sources of raw materials. But a Muslim fights only in the cause of Allah (SWT). That is, they fight to preclude oppression, mischief-making, chaos on earth.

3. It is not legitimate to go beyond the limit during and after war. Islam orders to kill as it should be when necessary. For example, it prohibits over doings such as torturing to death or to cut ears or nose off.

In another verse, Allah (SWT) announces:
And why should ye not fight in the cause of Allah and of those who, being weak, are ill-treated (and oppressed)? Men, women, and children, whose cry is: "Our Lord! Rescue us from this town, whose people are oppressors; and raise for us from thee one who will protect; and raise for us from thee one who will help! (An-Nisaa Surah, 4:75)

In this verse, it is advised to fight a country on the condition that it oppresses Muslims and prohibits them to live base on their religion freely. In the end of the war, Muslims become free from oppression and regain their freedom of religion and conscience; and the people of that country are granted freedom as to convert Islam or not to.

Finally, we could say that:

What is essential in Islam is not war but peace. However, war may be in question in some circumstances such as inflicting oppression on people, or a country is attacking any other. According to Islam, war is permissible in those conditions. War is not something that Islam invented when there was no war in the world. Those who claim that Islam is a religion of war are certain to come across the reality that there is war at any period of their history. In consequence, it is not a deficiency for Islam to have decrees of war but is perfection. In the verses, a reality such as war, which is inevitable to be away from and which is in fact primitive and savage, has been made more civilized and more humane.