"OFFENSIVE JIHAD: Where the Kuffar are not gathering to fight the Muslims, the fighting becomes Fard Kifaya, with the minimum requirement of appointing believers to guard the borders and the sending of an army at least once a year, to terrorise the Enemies of Allah. It is the duty of the Imam to assemble and send out an Army unit into the land of War, once or twice every year. Moreover, it is the responsibility of the Muslim population to assist him, and if he does not send an army he is in sin. And the Ulama have mentioned that this type of Jihad is for maintaining the payment of Jizya. The Scholars of the principles of religion have also said, "Jihad is Da'wah with a force and is obligatory to perform with all available capabilities, until there remains only Muslims or people who submit to Islam." DEFENSIVE JIHAD: This is expelling the Kuffar from our land and it is Fard Ayn, a compulsory duty upon all."
January 1, 1970
https://en.wikiquote.org/wiki/Jihad