In the last century, competition among the global powers has relied heavily upon the concept of war threat assessment. However, the ways in which these powers define security have differed among them, leading in some instances to miscommunication, conflict, and even war. In Without Warning, accomplished scholar Mikhail Alexseev compares the intelligence priorities of principal decision makers in such various parts of the world as the Mongol Empire and Sung China (1206-1220). Great Britain and France (1783-1800), and the United States and the Soviet Union (1975-1991). In his analysis, Alexseev reveals that while the leading powers see security primarily in military and economic terms, their challengers focus primarily on political vulnerabilities. As a result, Alexseev asserts, the world powers have consistently failed to detect or deter aggressive challenges.