"Islam is a western religion."
Other than historic incursions into "the west," triggering the Crusades, Islam has played no significant role in the practice of religion in the west, by westerners. That even remains so today, despite a fairly large wave of immigration. Islam certainly isn't an eastern religion, but to call it a western one is more than slightly peculiar, no matter how many quotes you might have mined describing it thusly.
It's a western religion because it is descended from the God of Abraham and because it recognizes Jesus as a prophet.
It is a rather great heresy, but no more so than Christian Science or LDS. It is rather belligerent, but it has conquered no more territory than Christianity.
It strikes me as medieval, but then what we call medieval was Christianity before secular governments arose.