With stronger pot, people can smoke less to achieve the same effect, thereby reducing their exposure to combustion products, the most serious health risk associated with marijuana consumption. Yet the ONDCP inexplicably warns that higher THC levels could mean an increased risk of respiratory problems.

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To bolster the idea that marijuana is more addictive today, the ONDCP notes that 16.1% of drug treatment admissions [in 2006] were for marijuana as the primary drug of abuse, compared to 6% in 1992. But referrals from the criminal justice system account for three-fifths of these treatment admissions, and marijuana arrests have increased by more than 150 percent since 1990.

By arresting people for marijuana possession and forcing them into treatment, the government shows why it has to arrest people for marijuana possession. That's our self-justifying drug policy in a nutshell.