These are three brief examples, but this story has been repeated wherever Islam has asserted itself. When Islam comes to a new nation, its purpose is not to adapt to the fabric of the host society, or to become just one religion among many equals. Its goal is to become the dominant religion. The Muslim belief is that once a territory has been under Muslim rule, it can never be relinquished again. And so former Muslim colonies such as Spain, Israel and the Balkans, are high on the list for reconquest. But make no mistake, any territory is fair game.
Further reading on Dar-al-Islam, Dar-al-Harb, and Dhimmitude: