I always find it quite embarrassing when right-wing politicians here in Germany come up with this or that does not belong to Europe. In all cases this only shows their geographical and historical ignorance. Kalmykia is a good example. Most of these politicians have never understood that Buddism has been part of Europe for centuries. My favorite example, however, is that they mostly do not know that we have had a perm…
With regard to Islam in geographical Europe, yes there is Tatarstan (and bits of adjacent regions), but Muscovy conquered that Muslim power in the mid 16th century and subsequently made it very clear that while Islam exists there, it is only at the mercy of Christian rulers. Historically, during the tsarist era Muslims were forbidden from trying to convert the Christian population.
Perhaps a better example of "Muslims have been in Europe for a long time" (excepting Ottoman converts, as they are seen as forced conversions/uninvited guests/traitors by nationalist demagogues) would be those Tatars (same name as the Kazan Tatars but not closely related) who settled in the Polish-Lithuanian Commonwealth, but again their impact on the surrounding culture was minuscule, and ultimately they assimilated into the Slavic-speaking Christian population.