The Islamic State militants didn’t explain their actions. But past statements have indicated that they view such ruins as creations of a polytheistic religion and culture they reject. This disregard for the heritage of “others” is sadly not a unique view: During the centuries of European exploration and colonization, many native shrines and artifacts around the globe were destroyed. The United Nations today designates World Heritage sites (such as Palmyra) in part to assert universal standards for preservation. U.N. member nations implicitly recognize the obligation of stewardship.