When the Muslims is a small quantity among another religion, one can live peacefully, but when there are more Muslims, then disagreements that lead to violence begin.
I can give you hundreds of examples. One famous example is that of Kosovo. It was historically a Serbian province. And for the Orthodox Christians around the world, Kosovo is extremely important. Remember the Battle of Kosovo, of 1389?
Things were normal until the Muslims became a majority. Once they became the majority, they started their ethnic cleansing campaign against the Christians. Now there are hardly any Christians left in Kosovo.
