That Italy can hold the Tripolitanian coast towns as long as her ammunition, her patience, and her public purse hold out, no one acquainted with the conditions of modern warfare will attempt to deny. Unless, however, the militant section of Islam, of which this region is the very focus, can be induced to acquiesce in an Italian occupation, the life of an Italian soldier who ventures out of range of his war-ships' guns will not be worth an hour's purchase. Hordes of fanatical, desert-bred Arabs, inured to hardship, deadly sun, scanty food, and dearth of water, mounted on swift camels and as familiar with the trackless desert as the woodsman is with the forest in which he works, ablaze with a religion which assures them that the one _sure_ way to paradise is to die in battle with the unbelievers, can harass the Italian army of occupation for years to come by a guerilla warfare. Even though Turkey agrees to surrender Tripolitania and to withdraw her garrisons from that province, Italy will still have far from smooth sailing, for the simple reason that she is not fighting Turks alone, but Moslems, and, as a result of her ill-advised slaughter of the Arabs, she has made the Moslem population of Tripolitania permanently hostile. Most significant of all, the Arab resistance to an Italian advance into the interior of the country will be directed, controlled, and financed by that sinister and mysterious power known as the Brotherhood of the Senussiyeh. To American ears the word “Senussiyeh” doubtless conveys but little meaning, but to the French _administrateurs_ in Algeria and Tunisia, and to the officers of the Military Intelligence Department in Egypt and the Sudan, it is a word of ominous import. Though the Brotherhood of the Senussiyeh is, without much doubt, the most powerful organisation of its kind in the world, so complete is the veil of secrecy behind which it works that comparatively little is definitely known as to its designs, ramifications, and resources. Briefly, it is a secret Moslem society, organised about a century ago by an Algerian dervish, Mohammed ben Ali ben Es Senussi, from whom it takes its name; its object is the restoration of the Mohammedan religion to its original purity, austerity, and political power, the first step toward which is the expulsion of the Christian from Moslem lands; its initiated members, scattered throughout the Mohammedan world, have been variously estimated at from five to fifteen millions; the present grand master of the order, Senussi Ahmed-el-Sherif, the third of the succession, is admittedly a man of exceptional intelligence, resource, and sagacity; his monastic court at Jof, in the oasis of Kufra, five hundred miles, as the camel goes, south of Benghazi and about the same distance from the Nile, is the capital of a power whose boundaries are the boundaries of Islam.