I remember learning this in a conversation I got into on the way home from University on the city bus with a fellow who was doing his doctorate in history, 2 years ago.
The figure for the U.S. in this table is wrong. It's closer to 7%, which puts the U.S. in the top 7. Everyone else in the top 7 are Muslim countries or Israel, which was stolen from Muslim countries by Jews supported by Christians.
By the way, don't get the wrong idea. the U.S. may be only 7th in military expenditure as a percentage of GDP, but we still spend well more than the rest of the world *combined* on "defense"/military expenditures. The reason we're seventh is that we have by far the largest GDP. This makes a certain sense--if you're the richest, and 2 billion people are living in extreme poverty, then of course you're going to have to build an increasingly expensive military fence to keep them out and maintain such an imbalance. In the same way keeping your house 40 degrees cooler or hotter than the outside temperature is a lot more expensive than than having it the same temperature, and also a lot more expensive than having it 10 or 20 degrees cooler or hotter than the outside temperature. As the difference in temperature increases, between inside and outside, it becomes increasingly expensive to maintain.