What is the fine-grained topic of the following text: As Iraqi officials are estimating the extent of the damage done by the Islamic State militants to one of the country's UNESCO World Heritage Sites, the ancient city of Hatra, a former US Foreign Service employee, Peter van Buren, has revealed that the US Army also wrought a lot of damage to some of the country’s historical landmarks. Only return the topic.
Damage to Iraq's historical landmarks by Islamic State militants and the US Army