This article from 2013 is, well, "interesting" to put it lightly: https://www.motherjones.com/politics/2013/05/contractors-385...
A company controlled by Dick Cheney made the most money in the Iraq & Afghanistan wars. It's probable that those wars would have been logistically impossible otherwise, considering how many contracts they held and how vital a role they played.
Someone said that control of a superior supply chain wins wars [or at least, delays their resolution]. But private contractors, not the US Military, control the supply chain. They supply virtually every aspect of the temporary-cities that are U.S. wartime bases. Without them, we can't have these wars. And the people who run them work in the highest levels of government. It's less conspiracy theory than blatant war profiteering.
I think this brings up two interesting points. (1) If you control the corporations that profit, and you influence the government's war policy as well as budget, you can create wars for profit. Would we even have these wars if contractors weren't involved? And (2), if the contracting companies "went away" tomorrow, would we still have the military might we imagine we have?