I'm not sure what part of my post you want proof on. Where the money goes is a matter of public record. You can see how much each contract is worth and how much was expended. You can see who the contractors were. You can see who owns that company. That chunk is easy to determine. The black contracts are of course not a matter of public record, but because they are generally much more sensitive work you can reason the requirements get much more stringent.

Regarding your second point, what are you referring to? US sales of arms to foreign entities? Yes the US is a major arms exporter... the US Government however isn't the seller, it simply wields the power to approve or disapprove of sales. The actual sellers are your Lockheed Martins, Boeings, Raytheons, Northrup Grummans, etc. Their only affiliation with the federal gov't is that the federal gov't is their main customer.