the u s is not the only nation with freedom of religion. unfortunately, some other nations do not have religious freedom and slaughter/suppress adherents of all religions or in the name of the state sponsored religion. perhaps eventually all religions will manage to kill off enough of the adherents of other religions to the point that the religious become an insignificant part of societies or leave only the non proselytizing or pacific type religions.
islam just needs to grow up like christianity did and stop advocating the conversion or slaughter of non muslims, but that might take a few centuries. it is only in the last few decades that christianity started embracing ecumenicalism
oh well