When the US government went full throttle into World War II, some got better deployments than others. If you got the short end of the stick, you were a G.I. parachuting into Nazi-occupied Poland. But if you were lucky, you were sitting in some cozy office, making hash oil and experimenting on it.

According to declassified government documents published in the Antique Cannabis Book, the OSS (Office of Strategic Services, which later became the CIA) tested the effects of THC extract as early as 1943 to see how useful it would be in prisoner interrogation.

A 1945 report says that half a dozen different drugs were tested on interrogation subjects and proclaimed “cannabis as the drug of choice.” Out of three different forms of cannabis, the OSS researchers liked “tetrahydrocannabinol acetate,” a liquid extract, the best.

Researchers found that subjects were more likely to open up if they didn’t know they were getting high. Interrogators injected the extract into cigarettes and gave these to their subjects without them knowing there was anything but tobacco inside. According to a classified documents, researchers found that an interrogator “should manipulate the situation in such a way that the subject does not become aware that he has been drugged or is behaving unusually.”

So the prisoner doesn’t know that they’re high or feel themselves loosening up. Meanwhile, the interrogator never gives any formal questioning. “It is essential that the subject does not know that he is being subjected to formal interrogation,” the report reads. “He should be led to believe that he is engaged in a friendly discussion of matters of common interest.”

As far as we can tell, these waxed-up cigarettes were never used by government interrogators on a wide scale, but they were seen as useful. The THC acetate was “not a perfect ‘truth drug,’” the report says. “However, the drug does produce a psychological state of relaxation, talkativeness and irresponsibility which might be extremely useful to a skilled interrogator.”

The report also says that an interrogator must be “familiar with the properties of the drug,” which sounds a lot like these OSS agents were getting paid to get high on their own supply. It’s not a bad deal for the interrogation subjects. It sure beats the hell out of modern interrogation techniques.

Photo via Flickr user Seattle Municipal Archives