VANCOUVER -- Riding high after U.S. states rejected measures to relax drug laws, drug czar John Walters came to Canada this week to talk tough about a new front in the drug war. Marijuana poses a greater danger to the United States than heroin, cocaine or amphetamines, said Mr. Walters, the director of the White House Office of National Drug Control Policy, in an interview yesterday in Vancouver. About 60 per cent of six million people who need treatment services for drug abuse in the United States are dependent on marijuana, he said. Earlier this month, Mr. Walters campaigned against...