Emile Tyan (1901-1977) studied law at St. Joseph University in Beirut, and received a doctorate in 1926 from the Faculty of Law at Lyon for a treatise on Islamic law. He became a professor of law in Beirut, and a politician, serving as a Lebanese minister of justice. Tyan was a major scholar of the Caliphate system noted, for his monumental works Le califat en regime sultanien (1956), and Sultanat et califat (1956). He also wrote a pellucid, remarkably compendious and unapologetic analysis of jihad for the venerable Encyclopaedia of Islam.
Tyan on the establishment of Islam’s totalitarian Caliphate system by jihad, and the nature of the uniquely Islamic institution of jihad, itself:
. . . [O]ne of the basic principles of Islam is that it must be extended to the whole world by conversion or at the least by submission to Islamic authority. The caliph has an obligation to promote and fulfill this universalism, if necessary by the force of arms. This is the meaning of holy war or jihad. From which it follows that Islamic sovereignty is at least potentially universal.
[from, Recueil de la Société Jean Bodin, V. 20, 1970, pp 503ff. (English translation by Nidra Poller, as “The monocratic system in Sunni Islam”)]
The Caliphate conserved its character as a religious institution, not in the sense of an organism of spiritual power or function, but quite precisely, in the sense that in the Islamic conception, the Caliphate, as the titulary repository of supreme sovereignty in both the religious and civil aspects closely bound up with each other, is an institution that constitutes an element of the faith. It is a fundamental element of Islam, the pillar on which rests the whole edifice and which conditions the organization and life of the Community. The Islamic faith includes belief in the necessity of the Caliphate as the titular organism of the civil and religious attributes of sovereignty.
[from Institutions du droit public musulman, Vol. II Sultanat et califat, Paris, 1956, p. 250. English translation by Malcolm Kerr, in Islamic Reform—The Political and Legal Theories of Muhammad Abduh and Rashid Rida, Berkeley, CA, 1966, p. 28, note 17.]
In [Islamic] law, according to general doctrine and in historical tradition, the djihad [jihad] consists of military action with the object of the expansion of Islam and, if need be, of its defense. The notion stems from the fundamental principle of the universality of Islam: this religion, along with the temporal power which it implies, ought to embrace to whole universe, if necessary by force.
The principle, however, must be partially combined with another which tolerates the existence, within the Islamic community itself, of the adherents of “the religions with holy books”, i.e., Christians, Jews and Madjus [q.v.; (Zoroastrians)]. As far as these latter are concerned the jihad ceases as soon as they agree to submit to the political authority of Islam and to pay the poll tax (jizya [q.v.]) and the land tax (kharadj [q.v.]). As long as the question could still, in fact, be posed, a controversy existed—generally resolved by a negative answer—on the question as to whether the Christians and Jews of the Arabian peninsula were entitled to such treatment as of right. To the non-scriptuaries, in particular the idolaters, this half measure has no application according to the opinion of the majority: their conversion to Islam is obligatory under pain of being put to death or reduced into slavery.
The jihad is a duty. This precept is laid down in all the sources. It is true that there are to be found in the Kuran [Koran] divergent, and even contradictory, texts. These are classified by the doctrine, apart from certain variations of detail, into four successive categories: those which enjoin pardon for offenses and encourage the invitation to Islam by peaceful persuasion; those which enjoin fighting to ward off aggression; those which enjoin the initiative in attack, provided it is not within the four sacred months; and those which enjoin the initiative in attack absolutely, at all times and in all places. In sum, these differences correspond to the stages in the development of Muhammad’s thought and to the modifications of policy resulting from particular circumstances; the Meccan period during which Muhammad, in general, confines himself to moral and religious teaching, and the Medina period when, having become the leader of a politico-religious community, he is able to undertake, spontaneously, the struggle against those who do not wish to join this community or submit to his authority. The doctrine holds that the later texts abrogate the former contradictory texts (the theory of naskh [q.v.]), to such effect that only those of the last category remain indubitably valid; and, accordingly, the rule on the subject may be formulated in these absolute terms: “the fight (jihad) is obligatory even when they (the unbelievers) have not themselves started it.”
Since the jihad is nothing more than a means to effect conversion to Islam or submission to its authority, there is only occasion to undertake it in circumstances where the people against whom it is directed have first been invited to join Islam. Discussion turned on the question as to whether it was necessary, on this ground, to address a formal invitation to the enemy. The general doctrine holds that since Islam is sufficiently widespread in the world, all peoples are presumed to know that they have been invited to join it. It is observed, however, that it would be desirable to repeat the invitation, except in cases where there is ground for apprehension that the enemy, thus forewarned, would profit from such a delay by better organizing his defenses and, in this way, compromising the successful outcome of the jihad
The duty of the jihad exists as long as the universal domination of Islam has not been attained. “Until the day of the resurrection,” and “until the end of the world” say the maxims. Peace with non-Muslim nations is, therefore, a provisional state of affairs only; the chance of circumstances alone can justify it temporarily. Furthermore there can be no question of genuine peace treaties with these nations; only truces, whose duration ought not, in principle, to exceed ten years, are authorized. But even such truces are precarious, inasmuch as they can, before they expire, be repudiated unilaterally should it appear more profitable for Islam to resume the conflict. It is, however, recognized that such repudiation should be brought to the notice of the infidel party, and that he should be afforded sufficient opportunity to be able to disseminate the news of it throughout the whole of his territory.
The jihad has principally an offensive character; but it is equally a jihad when it is a case of defending Islam against aggression. This indeed, is the essential purpose of the ribat [q.v.] undertaken by isolated groups or individuals settled on the frontiers of Islam. The ribat is a particularly meritorious act.
Finally, there is at the present time a thesis, of a wholly apologetic character, according to which Islam relies for its expansion exclusively upon persuasion and other peaceful means, and the jihad is only authorized in cases of “self defense” and of “support owed to a defenseless ally or brother.” Disregarding entirely the previous doctrine and historical tradition, as well as the texts of the Kuran and the sunna on the basis of which it was formulated, but claiming, even so, to remain within the bounds of strict orthodoxy, this thesis takes into account only those early texts which state the contrary (v. supra).
[from, Encyclopaedia of Islam, Edited by B. Lewis, Ch, Pellat, and J. Schacht; Assisted by J. Burton-page, C. Dumont, and V. L. Menage; Volume II, C to G, Fourth Impression, Leiden, E.J. Brill 1991, pp. 538-39]