j3375, all Muslims should act like the Prophet (ASWS). And when he had invaded a countery/city he would offer Islam to the people of that country/city if they were to embrace it alhamdulilah if not they would protect them as they were their own and they'd live with the Muslims in harmony. And God tell's Mohammad (SAWS) that he (the prophet (SAWS)) should do nothing to the kufar (the non believers ie. the atheists.) As he Allah, will take care of them.