American Military Spending

I just read in The New Yorker that American military spending is more than all other countries combined. (I keep hearing another statistic, like more than the next 17 or so countries combined?) But how are they arriving at this conclusion? I mean, they aren't counting all the weapons and military aid we're giving to other countries, right? I mean, that's not for our military, so surely that doesn't count, right? It really ought to be just for what we spend on our military. All the rest is just to be sporting for when we fight them later, isn't it? I know it's our money, but it's not really the same, is it? So I hope it doesn't count. Because we really ought not to be spending more than the next 20 or so countries combined, because that might seem, oh, I don't know, maybe a bit excessive? (Not that we don't need it, though, I'm sure. I've seen Battleship and those G.I. Joe movies, and those aliens and COBRA seem pretty dangerous. We've got to be ready when they strike!)