User blog comment:LurkerLordB/Religion in a world without Christianity/@comment-8815453-20120424042016/@comment-1630894-20120430041408

Hinduism would not have a threat from Islam (though they might not have that many more members as Zoroastrianism and Buddhism would both be bigger there). Other than India, Buddhism would be bigger, having spread overland (as would Taoism, to a lesser degree). However, I don't think the lack of Christianity would make the isolationist East Asian nations great colonizers, but with a POD so far back, their cultures could be different so who knows.