"There is only one place on earth which can be called the home of Islam (Dar-ul-Islam), and it is that place where the Islamic state is established and the Shariah is the authority and God's limits are observed, and where all the Muslims administer the affairs of the state with mutual consultation. The rest of the world is the home of hostility (Dar-ul-Harb). A Muslim can have only two possible relations with Dar-ul-Harb: peace with a contractual agreement, or war. A country with which there is a treaty will not be considered the home of Islam."
A Muslim's Nationality And His Belief By The Martyr Of Islam by Syed Qutb (http://islamicweb.com/resources/nationality.htm)