Offensive Jihad is jihad to expand the realm of Islam. As used by Muslims such as Abdullah Yusuf Azzam and Sayyid Qutb, offensive jihad means armed combat, and not spiritual or other forms of non-violent striving.
According to the Encyclopedia of the Orient, "While offensive jihad, i.e. attacking, is fully permissible in Sunni Islam, it is prohibited for some of the larger groups of Shi'i Islam, which consider only the Imam, now in occultation, as carrying the right to decide to go to war or not." .
Where the Kuffar [infidels] are not gathering to fight the Muslims, the fighting becomes Fard Kifaya [religious obligation on Muslim society] with the minimum requirement of appointing believers to guard borders, and the sending of an army at least once a year to terrorise the enemies of Allah. It is a 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 Daw'ah with a force, and is obligatory to perform with all available capabilities, until there remains only Muslims or people who submit to Islam."
There is no room to say that the basic aim of the Islamic movement was `defensive` in the narrow sense which some people ascribe to it today, defeated by the attacks of the treacherous Orientalists!
... Those who say that Islamic Jihad was merely for the defense of the `homeland of Islam` diminish the greatness of the Islamic way of life ...
Qutb believes Muslims were restrained from fighting for a brief time "in Mecca and in the early period of their migration to Medina," but that following this "Muslims were permitted to fight, then they were commanded to fight against the aggressors; and finally they were commanded to fight against all the polytheists," (which Qutb believes to include Christians and Jews). According to Qutb, this command is the final one for Muslims and is the one operative today.
Jihad in Islam, from the perspective of Islamic jurisprudence, is of two types: [Defensive jihad and] jihad initiated by the Muslims, which means raiding the world in order to spread the word that 'there is no God but Allah, and Muhammad is the Prophet of Allah' throughout the world. But this raid will not materialize in our era - the era of barbaric American capitalistic globalism - unless the Infallible, peace be upon him, is present.
But there are jurisprudents, both Sunnis and Twelver Shi'ites, who have said that the presence of the Infallible is not a prerequisite. If the objective and subjective circumstances materialize, and there are soldiers, weapons, and money - even if this means using biological, chemical, and bacterial weapons - we will conquer the world, so that 'There is no God but Allah, and Muhammad is the Prophet of Allah' will be triumphant over the domes of Moscow, Washington, and Paris."