A fairly useful metaphor for the issue is Northern Ireland. A powerful foreign invader bit off six counties of Ireland and labeled it "Britain," called the people "British," and started importing Protestant English and Scottish settlers to supplant the local Irish.

Now Irish are a minority in many areas of "Northern" Ireland.

Though often referred to as a religious conflict, the Irish Troubles weren't really religious at their root, but cultural and economic. And of course people just being plain pissed off at having been invaded.