It notes that since the start of the intervention in Afghanistan in October 2001, Pentagon spending has totalled $14 trillion, with the US war budget increasing between 2002 and 2003 by more than the entire military spending of any other country. Between one-third and one-half of that total was pocketed by defense firms, which provided logistics and reconstruction, private security services and weapons – along the way, these contractors habitually engaged in "questionable or corrupt business practices," including fraud, abuse, price-gouging and profiteering.
Wartime conditions meant standard contract processes were circumvented – bidders, bids, and subsequent delivery weren't subject to significant oversight, so fleecing the Pentagon was extremely easy, particularly for well-connected companies with government ties.
Lockheed Martin, Boeing, General Dynamics, Raytheon, and Northrop Grumman have in recent years been awarded between a quarter to a third of all Pentagon contracts. It's surely no coincidence that four of the past five US Defense Secretaries previously worked at one of the 'big five'.