"Islam generally divides the world into two 'houses,' the 'house of Islam' and the 'house of war.' Although not of its own choice, the U.S. as the sole remaining superpower, and a non-Muslim state, is the modern leader of the 'house of war.' The context of Islam's duality and the unavoidable threat it poses to U.S. national security can be understood through the lens of lifelong scholars. The Intelligence Community must orient itself to this menace. Generally, Islam is peaceful within the 'house of Islam'; however, it is prepared to extend itself into the 'house of war' by force or 'Jihad' (extensively discussed later). 'This bipartite division of the world into an abode of peace and an abode of war finds a parallel in the communistic theory of Soviet Russia.' Historically, there have been periods when Islam has abandoned forceful expansion, or has made accommodations that, at least temporarily, provide a middle ground between the two 'houses.' Generally, when Islam is on the advance, Jihad accelerates, and when the spread of Islam is on the decline, it stops. Given the undesirability of a conflict between the U.S. and Islam, it is imperative that U.S. policymakers understand the threat that comes with leading the 'house of war,' while maintaining awareness of the historical middle-ground."
Discussion Paper Number 13
National Defense Intelligence College: http://www.dia.mil/college/