The number of Defense Department employees and contractors with security clearances has dropped by 20 percent over the last three years, according to data published by the Office of Management and Budget.
The sharp decline reflects a concerted effort by the Obama administration to tighten the background-check process in the aftermath of leaks of classified information by Edward Snowden and Chelsea Manning, as well as the 2013 Navy Yard shooting by an IT contractor with a security clearance.
