 The U.S. has used large amounts of aid and counterinsurgency training to enhance stability and reduce violence in war-ravaged Colombia, in what has been called "the most successful nation-building exercise by the United States in this century".The U.S. intervened in the 2011 Libyan Civil War by providing air support to rebel forces.There was also speculation in "The Washington Post" that President Barack Obama issued a covert action, discovering in March 2011 that Obama authorized the CIA to carry out a clandestine effort to provide arms and support to the Libyan opposition.