Military history of the Crusader states
The Seljuk–Crusader War began when the First Crusade wrested territory from the Seljuk Turks during the Siege of Nicaea in 1097 and lasted until 1128 when Zengi became atabeg of Aleppo. At the latter date, the chief threat to the Crusaders from the east and north became the Zengids. The conflict was generally fought between European Crusaders and the Seljuk Turks and their vassals. The Muslim Syrian emirates occasionally allied themselves with the Christians against rival states.
Perpetual war
The Crusades arose as European expansion was growing at the peak of unified Islamic dominance. As the Crusades marked the beginning of conflict between the Christian countries and Islamic countries, some say that the so-called war on terror is a continuation of the Crusades. On September 16, 2001, in a speech, President Bush referred to the War on terror as a crusade. He said: