During the Cold War the CIA started researching ways they could turn Americans into CIA-controlled "superagents," people who could carry out assassinations and who wouldn't be affected by enemy interrogations. Under what was known as the MK-ULTRA project, CIA researchers experimented on unsuspecting American (and Canadian) citizens by slipping them psychedelic drugs, including LSD, PCP and barbiturates, as well as additional — and additionally illegal — methods such as hypnosis, and, possibly, chemical, biological, and radiological agents. Universities participated, mostly as a delivery system, also without their knowledge. The U.S. Department of Veterans Affairs estimates 7,000 soldiers were also involved in the research, without their consent.