You should read this book: Confessions of an Economic Hit Man. It's shocking and insightful.
Basically the book explains and teaches that when you hear, for example, that Egypt is getting a billion US$ in military aid, that's not what it sounds like. We are not sending them a check for a million bucks. We are actually sending the million bucks to US millitary corporations.
Why? Because the funds that Egypt gets can only be spent with specific US companies on specific items, either hardware or service contracts. And moreover the books explains that often the recipient country doesn't even want what they are required to purchase or the project that they are required to undertake, lets say a new highway, bridge, airport or whatever.
So read the book and also, keep that in mind when you learn for example that Senators backing war in Syria are flush with defense industry cash « Watchdog.org:
According to an analysis by MapLight, which tracks lobbying and campaign contributions in Congress, senators who voted in favor of the resolution received, on average, 83 percent more money from defense contractors and other defense interests than senators who voted against the resolution.