Battling Islamic State militant is expensive. This week, officials from the Pentagon revealed that since last summer when the fight against ISIS began, the U.S. has spent more than $2.7 billion. That’s more than $9 million every single day, or $375,000 every hour since August. Most of that money—$1.8 billion—has been used by the Air Force. The second biggest single cost at $646 million, has gone toward munitions. According to CBS News, military officials released the report as lawmakers in Washington rejected new legislation that would have temporarily prevented combat-related spending until Congress passed the latest resolution on war powers …