When you think about the cost of war, if your like me, you probably never think about the fine details, like the cost of air conditioning.

The amount the U.S. military spends annually on air conditioning in Iraq and Afghanistan: $20.2 billion, according to a former Pentagon official. Read more about the cost of war after the jump.That's more than NASA's budget. It's more than BP has paid so far for damage from the Gulf oil spill. It's what the G-8 has pledged to help foster new democracies in Egypt and Tunisia.

When you consider the cost to deliver the fuel to some of the most isolated places in the world — escorting, command and control, medevac support — when you throw all that infrastructure in, we're talking over $20 billion.

Now it's important to note that wrapped up in the $20 billion figure are all kind of other expenditures – for instance, the cost of building and maintaining roads in Afghanistan, securing those roads, managing the security operations for those roads. That all costs a lot of money and is part of the overall war effort in Afghanistan. If you have ever wondered why war is so expensive, it's because there are more things involved than just bullets.