http://mercatus.org/publication/comprehensive-look-defense-spending-fy-2012

A Comprehensive Look at Defense Spending, FY 2012

Veronique de Rugy | Jan 29, 2013

How much are we actually spending on national security and defense–related programs? A whole lot more than you think.
This chart puts into perspective the amount of spending that is not being accounted for in widely cited figures by the Pentagon (DOD) and the Office of Management and Budget (OMB). Using data calculated by Winslow Wheeler of the Project on Government Oversight
, line items from other areas of the federal budget relevant to defense and security issues are added to the FY 2012 base. The findings suggest that reported defense spending figures underestimate the overall cost of defense and national security programs by up to $400 billion in FY 2012.