Long before he was in a position to change his country’s policies, Barack Obama had firm views on a complex problem: “The war on drugs has been an utter failure. We need to rethink and decriminalize our marijuana laws. We need to rethink how we’re operating the drug war.”

That was in January 2004, during a debate at Northwestern University, when he was running for a seat in the U.S. Senate. To make sure his student audience understood his position on the controversial issue, Obama added: “Currently, we are not doing a good job.”

To look at a classic flip-flop, forward to April 2012 and a summit of Latin American leaders, several of whom have become vocal critics of the U.S.-driven war on drugs, in the Colombian city of Cartagena. More than three years into his presidency, Obama made clear that he is not in favor of legalizing drugs or of ending policies that treat drug users as criminals.

“I don’t mind a debate around issues like decriminalization,” he said at the Cartagena summit. “I personally don’t agree that’s a solution to the problem.” Decriminalization means scrapping criminal penalties for the use of drugs. It falls short of legalization which, in its purest form, means the abolition of all forms of government control of drugs. Obama is against that, too. “I don’t think that legalization of drugs is going to be the answer,” he said.

So what is the answer? In his first year in office, Obama talked about placing more emphasis on curbing demand – the United States is the world’s richest market for illicit drugs – and less on enforcing punitive laws that filled American prisons with drug offenders and helped turn the country into the world’s chief jailer. It has 5 percent of the world’s population and 25 percent of the world’s prisoners.