> Such pundits also ignore the inconvenient fact that many Muslim majority countries often have very old Christian communities yet the same is not true of Christian majority countries. I wonder why?

What? Muslim majority countries with old Christian communities are because Christianity spread widely in the Middle East after 0 AD, until 7th century AD when Islam came around. Of course there will be residual Christian communities there. But the Christian majority countries became Christian before 7th century AD and were able to halt the spread of Islam post 7th century (Europe), or the country was colonized after the fact by previous Christian countries (USA, South America) where Islam never made it.