Book excerpt: This study analyses German and Ottoman efforts to promote a Muslim uprising in the Ottoman Empire and the Entente colonies in the First World War through intelligence and propaganda operations. Where appropriate, reference will be made to similar activities carried out by the British. These activities ended in failure. Germany over-rated the power of Pan-Islam and did not succeed in producing the desired rebellions. Britain, on the other hand, underrated Ottoman internal cohesion, and overrated the appeal of Arab nationalism to gain the support of the Ottoman Arabs for Britain's ends.