Today marks the fortieth anniversary of the infamous speech in which President Nixon committed to waging “a new, all-out offensive” against drug abuse, which he declared “public enemy number one.” This moment is widely regarded as the unofficial launch of America’s spectacularly unsuccessful and costly global war on drugs.

If ever there was a time to consider exit strategies from a war, this is it. The war on drugs has cost roughly $1 trillion. It has resulted in tens of millions of arrests, put millions behind bars and driven the growth of a massive prison-industrial complex that now lobbies for the perpetuation of this failed war.

It has precluded the sorts of public health policies that might have prevented hundreds of thousands of people in this country from dying of AIDS and other infectious diseases as well as overdoses.

And it has legitimized gross violations of civil liberties and human rights in the United States and abroad; generated a global illicit drug market worth roughly $300 billion annually; and produced levels of crime, violence and corruption in many parts of the world that far exceed anything seen during the Prohibition era.

As with the war in Afghanistan, now approaching its tenth anniversary, few in government want to celebrate this anniversary. At best they can point to President Nixon’s impressive commitment to expanding treatment for addicts even as he dramatically expanded the punitive components of the nation’s drug policy. But claims that the war on drugs has accomplished much good falter in the face of meaningful evidence. And no one dares claim that the war has been won or even that there’s any light at the end of the tunnel. As The Onion once put it, “The War on Drugs Is Over: Drugs Won.”

This anniversary is being “celebrated,” however, by its critics. On June 2, the Global Commission on Drug Policy released an extraordinary report calling for transformative changes in the global drug prohibition regime, including not just alternatives to incarceration and greater emphasis on public health approaches but also decriminalization and experiments in legal regulation. The members of the commission included former UN Secretary General Kofi Annan; Richard Branson, founder of the Virgin Group; and four former presidents, including the commission’s chairman, Fernando Henrique Cardoso of Brazil. The US members included former Secretary of State George Shultz and former Fed chairman Paul Volcker. Never before has a group of such distinction recommended such far-reaching reforms of global drug policy.

The release of the report generated headlines and other media coverage worldwide, unlike anything ever seen before regarding drugs and drug policy. The commissioners made clear that they hoped their bold initiative would open up new political space in which not just former presidents and ministers but also those still in office will begin to voice similar sentiments.

All across the country this week are rallies and demonstrations calling for an end to the nation’s war on drugs. Activists for drug policy reform are recruiting local elected officials, clergy and people affected by the war on drugs to speak out and educate fellow citizens. Among the most persuasive of these are parents whose children are struggling with drug addiction, who have seen up close how devastating drugs can be but who also see clearly that the war on drugs did nothing to help and much to hurt their children and so many others.

This is how the war on drugs will end: with elder statesmen calling for radical change, and millions of victims of the drug war saying enough is enough, and fiscal conservatives tiring of the expense, and civil rights advocates embracing reform as part of their agenda, and young people rejecting the war as the folly of their elders, and elected officials deciding it’s time to step out—and tens of millions of parents concluding that their children and the future of our society are better served by policies that rely dramatically less on criminal sanctions and harsh punishments and much more on science, compassion, health and common sense.

Not so long ago, members of Congress competed to introduce ever tougher and more costly drug laws. Now we see a growing competition and collaboration to introduce bills rolling back the drug war. Much the same is happening in state legislatures across the country. And public support for removing marijuana entirely from criminal law is growing rapidly—from 36 percent in favor and 60 percent against in 2005 to 46 percent in favor and 50 percent against late last year (according to Gallup’s polling). It’s quite possible that the 2012 elections will include at least one victory for a state ballot initiative to regulate marijuana like alcohol.

I’m not prepared to say we’re at the tipping point. But never before have I felt so optimistic about prospects for major reform of drug policy in the United States and around the world.