In accordance with Shariah, once ground has been taken for Islam, it can never revert to the non-Muslim Dar al-Harb, literally the House of War.

CENTERFORSECURITYPOLICY: A shrine to Shariah?

Remember that the Islamic term for such lands is Dar al-Harb, the House of War, and it signifies that all such communities are targets, in the Islamic bull's-eye, for eventual conquest and subjugation to Islamic law.

CENTERFORSECURITYPOLICY: Ignoring the call to Islam will bring jihad

For liberal-minded Muslims, the old split between Dar al-Islam (the realm of Islam) and Dar al-Harb (the realm of war) hardly applies to an era in which some of the happiest adherents of their faith live as minorities.

ECONOMIST: Islam and Switzerland