*The US Drug Enforcement Agency classifies all C. sativa varieties as "marijuana." While it is theoretically possible to get permission from the government to grow hemp, DEA would require that the field be secured by fence, razor wire, dogs, guards, and lights, making it cost-prohibitive.

*The US State Department must certify each year that a foreign nation is cooperating in the war on drugs. The European Union subsidizes its farmers to grow industrial hemp. Those nations are not on this list, because the State Department can tell the difference between hemp and marijuana.

*Hemp was grown commercially (with increasing governmental interference) in the United States until the 1950s. It was doomed by the Marijuana Tax Act of 1937, which placed an extremely high tax on marijuana and made it effectively impossible to grow industrial hemp. While Congress expressly expected the continued production of industrial hemp, the Federal Bureau of Narcotics lumped industrial hemp with marijuana, as it's successor the US Drug Enforcement Administration, does to this day.

*Over 30 industrialized democracies do distinguish hemp from marijuana. International treaties regarding marijuana make an exception for industrial hemp.

* Canada now again allows the growing of hemp.