This is a common claim you hear, but it is often pointed out as a lie.
So I checked.
Yes, the US officially spends 687 billion for defense. This works out as more than the top 20 defense spending countries.
But if you add up the rest of the countries (here) you just get 875 billion!
Most people, if they looked at the US budget would think 875 billion is a extrememly conservative estimate of our defense spending. After all there is the VA (100 odd billion), parts of the DOE, the Interior, Treasury (retirement bennefits), NASA, State Department, Homeland Security, share of debt interest, and surely the EPA, not to mention other black budget security items we have no knowledge of - that can easily go to 875 billion. Then there are things like the opportunity costs of the people coming back from wars ending up unemployed or homeless.