For decades now, the evolving role of congressional oversight of US intelligence has involved major clashes and scandals, from the Iran-Contra affair of the 1980s to the intelligence abuses that led to the 2003 war in Iraq.

Central to all of these clashes are attempts by intelligence agencies, the president and the executive branch to withhold damning information from Congress. Another common element is the use of civilians to carry out presidential or intelligence agency agendas.