In the answer to question no. 20214 there is a discussion of the rulings on jihad and types of jihad. It says that jihad may be an individual obligation (fard ‘ayn) if the enemy attacks the Muslims, and in that case fighting them becomes an obligation on every Muslim, and the permission of the ruler is not required in that case.
As for jihad that is aimed at conquest and calling the kuffaar to Islam, and fighting those who refuse to submit to the rule of Allaah, the permission of the ruler is essential in this case, thus things will be controlled.
Ibn Qudaamah (may Allaah have mercy on him) said:
The matter of jihad is in the hands of the ruler and his ijtihaad, and the people must obey him in whatever he sees fit with regard to that. End quote. Al-Mughni (10/368).
The permission of the imam is to prevent the chaos that may result if some of the Muslims declare war on the enemies of Allaah without taking into account their circumstances and strength and the strength of their enemy.
The scholars of the Standing Committee said:
Jihad to make the word of Allaah supreme and to protect the religion of Islam and make it possible to convey it and spread it and protect its sanctity is an obligation on everyone who is able to do that. But it is essential that the troops be organized and sent in an orderly fashion, lest it lead to chaos and incidents that bring unfortunate consequences. Hence initiation of and engagement in jihad is the responsibility of the ruler of the Muslims, and the scholars must encourage him. If he initiates the jihad and mobilizes the Muslims, then the one who is able to do so must respond to the call, sincerely seeking the Countenance of Allaah, and in the hope of supporting the truth, and to protect Islam. The one who stays behind when the call for jihad is given and has no excuse, is sinning. End quote.
Fataawa al-Lajnah al-Daa’imah (12/12).
If the people come together in response to the call of their ruler, that will increase them in strength, in addition to the fact that they are Islamically obliged to obey him in whatever does not go against the laws of Allaah. Thus the Muslims will be united in jihad, supporting Islam and defending the laws of Allaah.
Shaykh al-Islam Ibn Taymiyah (may Allaah have mercy on him) said:
It should be noted that appointing a leader to run the people’s affairs is one of the greatest of religious duties, without which no religious or worldly matters can be established, because the best interests of the son of Adam cannot be achieved without coming together, because they need one another. When they come together, it is essential to have a leader. The Prophet (peace and blessings of Allaah be upon him) said: “If three people set out on a journey, let them appoint one of them in charge.” Narrated by Abu Dawood from the hadeeth of Abu Sa’eed and Abu Hurayrah. Imam Ahmad narrated in his Musnad from ‘Abd-Allaah ibn ‘Amr that the Prophet (peace and blessings of Allaah be upon him) said: “It is not permissible for three people to be in the wilderness without appointing one of them in charge.” The fact that it is obligatory to appoint one person in charge of a small temporary group whilst travelling indicates that this is essential in all kinds of groups. And Allaah has commanded us to enjoin what is good and forbid what is evil, which can only be achieved from a position of strength and authority, and the same applies to all the other things that He has enjoined, such as jihad, justice, establishment of Hajj, Jumu’ah and Eid, as well as supporting those who are wronged or oppressed, and carrying out hadd punishments – it cannot be achieved except from a position of strength and authority. Hence it was narrated that “the ruler is the shadow of Allaah on earth” and “Sixty years with (even) an unjust ruler are better than one night without a ruler.” Experience proves that this is so. End quote.
Majmoo’ al-Fataawa (28/390, 391).
Shaykh Muhammad ibn ‘Uthaymeen (may Allaah have mercy on him) said:
It is not permissible for the army to set out on a campaign without the permission of the ruler, no matter what the situation, because the ones to whom the command to fight and engage in jihad is addressed are the rulers, not individuals. Individuals have to follow the decision-makers. So it is not permissible for anyone to fight without the permission of the imam, except in the case of defence. If the enemy attacks them suddenly and they are afraid of his evil, then they may defend themselves, because fighting becomes an individual obligation in that case.
The reason why that is not permitted is because the matter of jihad is the ruler’s responsibility, and fighting without his permission is a transgression against his rights and over stepping the mark. If it were permissible for the people to fight without the permission of the ruler, that would lead to chaos. Everyone who wanted to would mount his horse and go fight, and if the people were allowed to do that it would lead to many negative consequences. Some people would equip themselves on the grounds that they want to fight the enemy but their real aim would be to rebel against the ruler, or to spread evil by attacking another group of people, as Allaah says (interpretation of the meaning):
“And if two parties (or groups) among the believers fall to fighting, then make peace between them both”
For these three reasons and others it is not permissible to fight without the permission of the ruler. End quote.
Al-Sharh al-Mumti’ (8/22).
And Allaah knows best.