Do you think it would be a good idea to conquer islamic countries & convert them into a non religious country?

isn't that what spaniards did with the aztecs? they conquered and converted them in christianity, what about doing the same thing with muslim countries? but instead of converting them in christianity, we convert them in a non rleigious country, i think that would be even more peaceful... no more 9/11, terrorists who die for Allah, women covering them up, etc.