Muhammad’s intelligence service eventually rivaled that of Byzantium and Persia, especially when it came to political information. He reportedly spent hours devising tactical and political stratagems, and once remarked that “all war is cunning,” reminding modern analysts of Sun Tzu’s dictum, “all war is deception.” In his thinking and application of force Muhammad was a combination of Karl von Clausewitz and Niccolo Machiavelli, for he always employed force in the service of political goals. An astute grand strategist, he used nonmilitary methods (alliance building, political assassination, bribery, religious appeals, mercy, and calculated butchery) to strengthen his long-term position, sometimes even at the expense of short-term military considerations.
Muhammad’s belief in Islam and his own role as the “Messenger of God” revolutionized Arabian warfare and resulted in the creation of the ancient world’s first army motivated by a coherent system of ideological belief. The ideology of holy war (jihad) and martyrdom (shahada) for the faith was transmitted to the West during the wars between Muslims and Christians in Spain and France, where it changed traditional Christian pacifistic thinking on war, brought into being a coterie of Christian warrior saints, and provided the Catholic Church with its ideological justification for the Crusades. Ideology—whether religious or secular—has remained a primary component of military ventures ever since.