To say Islam has no relationship to the West - whoever that is these days - is nonsense.

Indeed.  Islam and Muslims have played a very large part in the history of the West.  It was Muslim governments which ruled all or part of Spain for 781 years.  It was the Muslim residents of Spain, and the xenophobia of the Spanish royalty which brought about the Spanish Inquisition.  It was a Muslim Ottoman army which sieged Vienna in 1529 and 1683, and almost caused the collapse of Christian rule in Europe.

When Columbus left Spain (seems to pop up a lot) in 1492, he was after two things:

1. Gold and natural resources to steal.
   
2. The supposed subjegation of the Muslim Indian "threat" to Spain.

The only way Columbus could have gotten funding is by making Isabella and Ferdinand believe that Muslims were going to attack, seeing as Granada had just fallen.

So the notion that Muslims have had no bearing on Western history is ridiculous.