The war of Egyptians with Israelis, Pakistanis versus Hindus, and the conflict between Turkish-origin and Greek-origin Cypriots are recent instances where the ideals of Jihad have been introduced.
[Christianity]
Pope Urban II called for the first crusade in 1095. After that, until the Reformation, pope after pope called upon Christian armies to attack Muslim lands. Subsequent popes knew full well that the first crusade had resulted, as the chroniclers said, in the blood of Muslims flowing over the temple mount. Yet for centuries these extremely violent conflicts were initiated by the popes, and indeed imposed as a moral condition on monarchs who faced excommunication if they refused to go.
[Islam]
The notion of religious justification for war persists, and threats of Jihad, or holy war, were still heard in the second half of the 20th century. While the influence of the mullah, mufti and other Moslem jurists, theologians and intellectuals is to internalize the Jihad and thus make it a personal struggle to attain moral improvement by self-conquest, the lack of restraint of some popular leaders, militarists, fundamentalists and oil supported politicians in invoking the traditional fourth way appeals to the emotions of the uneducated and threatens peaceful solutions to problems of Islamic and world concern.
Where Shiite Moslems fight Sunni Moslems, as in Lebanon, or in the case of Iran versus Iraq, each faction may also invoke the Jihad tradition, not unlike the clerically-blessed conflicts of Christian Europe. In 1990, Saddam Hussein, as president of Iraq declared a jihad against the forces arrayed against him.
In May 1997 during an interview with CNN, Osama Bin Laden reaffirmed his call for a holy war against Americans. "We have focused our declaration of jihad on the U.S. soldiers inside Arabia. The U.S. government has committed acts that are extremely unjust, hideous and criminal through its support of the Israeli occupation of Palestine." In February 1997 Bin Laden threatened holy war against the U.S. in an interview on the British documentary program, Dispatches. "This war will not only be between the people of the two sacred mosques and the Americans, but it will be between the Islamic world and the Americans and their allies because this war is a new crusade led by America against the Islamic nations."
The tendency for a nation to arrange divine endorsement of its defensive or offensive wars is known from antiquity, and was probably a characteristic of primitive man as exemplified by the American Indian war dances and other rites invoking supernatural help. However there is a difference of scale when one moves from the single, tribal level to levels of tribal confederations or nations. Religious fervor invoked on this scale can abet an enormous amount of bloodletting: the Crusades illustrate this. Islamic emphasis on the sword is seen by the conquests in its first thousand years. The wars of the Turkish Ottoman Empire (1300-1922), while not specifically Jihads, show such characteristic features as the desecration of the Hagia Sophia after the capture of Constantinople (1453); forced conversions to Islam over the centuries; and the genocidal massacres of over 2 million Catholic Armenians (1894-1896, 1915-16). Even where Jihad is not officially proclaimed, fighters may call themselves 'mujahidin' or holy warriors and circumvent the Koranic protection extended to Christians and Jews, as in the Six Days War with Israel.
Muslims believe that the solution to the problem of Palestine is a holy war against Israel and all the powers that support the occupation of Palestine.
Pope Urban, in calling for the first crusade, did not know how the crusaders would behave, and thought he was defending Christians in the East.
The use of the sword is the Islamic fourth way of performing the religious duty of defending and propagating the faith. The first three means are by the heart, by the tongue and by the hand.