Recent renewed interest in the First World War has encouraged innovative research on the global proportions of this devastating conflict; however, the Italo-Ottoman War—a conflict over the territory that is now Libya—remains an obscure footnote even in studies of the war in the Middle East. Yet, the war for Libya became a global cause célèbre attracting support and aid for the embattled Ottoman regime from diverse locations. This paper resituates the Italo-Ottoman War as the opening conflict and an enduring struggle in a decade of incessant warfare in the eastern Mediterranean (1911-1923) that ultimately reshaped the region. The effective coordination between Ottoman forces and their local allies in Tripolitania and Cyrenaica, most especially with the Sanūsiyya order, and the initial global subvention of the Ottoman war effort by Islamic aid organizations, such as the Ottoman and British Red Crescent societies, convinced the Ottoman government of the vitality of Pan-Islamism (İttihad-ı İslâm) in the defense of its lands from European encroachment. Further, it committed the Unionist government to an asymmetric strategy of warfare that relied upon nontraditional forces. Libya remained a site of conflict despite the Italo-Ottoman Peace of Ouchy in 1912, and the Ottoman government and military continued their surreptitious support of local volunteers to challenge Italian claims to the land. While Italy’s coffers nearly ran dry fighting their war for colonial expansion, the defense of Libya cost the Ottoman treasury very little and bolstered the position of war hawks in Istanbul. By 1915, the Ottoman volunteer forces in Libya played a pivotal role in Enver’s failed Sinai campaign. Early successes with irregular forces in Libya became a model for continued Ottoman expansion despite devastating losses on other fronts. My paper, through an examination of Ottoman military and humanitarian correspondence with commanders of local insurgent forces during the campaign, illustrates how the war in North Africa forged ties between Ottoman officers and local, Arab volunteers in the region and accelerated the assembly of global networks of Islamic aid that played an important role in the events of the First World War and the Ottoman strategy of resistance after 1918. Such an approach underscores the significance of Rome, Istanbul, Tripoli, and Benghazi in charting the trajectory of the First World War in the Mediterranean.