DISTRICT OF COLUMBIA:  A high-ranking State Department official called for “flexible” interpretations of international drug control treaties at the United Nations in New York City last week, citing marijuana legalization in Colorado and Washington.

Assistant Secretary of State William Brownfield’s Oct. 9 remarks were the third time this year he has made such a call. And the high-profile venue underscores the pressure that state legalization efforts have put on the U.S. to allow other countries to amend strict, decades-old international drug control treaties.

Brownfield said one pillar of the new U.S. approach on drug policy is to “accept flexible interpretation” of U.N. drug treaties.

“How could I, a representative of the government of the United States of America, be intolerant of a government that permits any experimentation with legalization of marijuana if two of the 50 states of the United States of America have chosen to walk down that road?” said Brownfield.

Between Brownfield’s remarks last week and two similar speeches in March, the official U.S. diplomatic stance is clearly shifting toward the position that the drug control treaties don’t need to be interpreted strictly.

“To now have the United States government emerging as a defender and even champion of flexibility in interpreting the conventions, that represents a major step forward,” said Ethan Nadelmann, executive director of the Drug Policy Alliance.

For decades the U.S. sought to impose stern prohibitionist policies not just on itself but on any country daring to take a new tack on drugs. The U.S. backed a harsh 1988 U.N. treaty, poured billions into counter-narcotics operations in Latin America and Asia, and opposed even modest efforts like decriminalizing the traditional consumption of the coca leaf in Bolivia. As recently as March 2012, the U.S. Embassy in Guatemala rebuked President Otto Perez Molina for proposing drug legalization.