False intelligence claiming that Iraq was trying to buy uranium yellowcake from Niger was a key element in the justification for war with Iraq. Ambassador Joseph Wilson debunked this claim in a New York Times op-ed piece in 2003. Shortly thereafter, his wife Valerie Plame Wilson was outed as a CIA undercover officer. Her work in tracking actual Weapons of Mass Destruction was thus destroyed.
The Wilsons have sued several members of the Administration, but the case has been extensively delayed. Dick Cheney's Chief of Staff Scooter Libby was convicted of perjury in covering up the White House's involvement in outing Plame, but George W. Bush commuted Libby's sentence.
White House involvement in outing Plame and commuting Libby's sentence are widely regarded as impeachable offenses.