Therefore...
Therefore, according to Ithna`Ashari law, a war cannot be started unless specifically authorized by the Prophet or Imam himself, and that also to the limits prescribed by that Representative of Allah. After all, life is a creation of Allah and it should not be destroyed unless it has been authorized to do so by a Representative of Allah. Accordingly, the Holy-War is forbidden for the Shi'ah Ithna `Ashari during the period when our Imam is hidden from us.
The Prophet himself never started any war unless it was thrust upon him by the enemies. A study of the map of Arabia will show the actual facts. As I have mentioned earlier, when the Prophet took refuge in Medina, the Meccans became infuriated because they could not satisfy their anger against him. So they made repeated attacks on him. The battle places of three important wars will tell the story. The first was `Badr' was fought at Badr in the second year of Hijrah.
Badr is 30 miles from Medina and 220 miles from Mecca. Is there any doubt that the Meccans were the aggressors? The second war named ` Uhud' was fought next year at Uhud. Uhud is 3 miles from Medina and 247 miles from Mecca. Three years after Uhud, Medina was surrounded by Meccans and Jews for about one month. They had come 250 miles from Mecca to attack Medina. Is there anybody who can say that the Prophet should not have fought in self-defence?
The first ayah of Qur'an permitting the war, after fourteen years of continual oppressions, speaks for itself. Qur'an says: "Permission to fight is given to those upon whom war has been thrust, because they are oppressed ... " (22:39). Regarding those wars that were fought after the death of the Prophet to conquer neighbouring countries, everybody knows that our Imams had nothing to do with them. Our Imams were the right authority to allow or disallow those wars. But they had no political power.
And all those wars were fought without their authorization. So, according to the Ithna`Ashari law, all such wars were political manoeuvres; they were not Holy-Wars or Religious Jihad. And Islam is not responsible for them. To discourage such unauthorized wars, it is laid down that any booty obtained in such wars will not belong to the fighters. Instead, all of it will vest in the Prophet or Imam, as his personal property; and he may dispose it according to his own discretion.
The Holy Prophet sometimes in such circumstances used to return the booty to its former owners.