That is taught as a proud part of Islamic history!
Analyse all events and you will find that most of the "sacred jihads" had this element.
Well said, Political Islam is a dividing force which causes fragmentation of community. The first frictions were evident in Medina right after Prophet death - which clearly implies that political Islam even failed its Prophet.
the enightment and renaissance in europe was all about separting church and state.
that happneed only 1500 years after christ. similarly now maybe its time for islamic renaissance.
but one difference i that the christians are only blossomed for last 400 yrs or so. islam had already blossomed some 800 years ago . wonder if there is a chance for a second coming. good if that happens.
so as you point out.. politics and islam should separate. islam should be a private and spiritual affair rather than policy of state or govt.