One of the least discussed issues in the presidential campaign is the war on drugs. That's unfortunate, because that crusade has been an expensive catastrophe both domestically and internationally. During the decades since Richard Nixon declared a "war" on illegal drugs in 1971, the United States has spent nearly one trillion dollars trying to eradicate the drug trade, filled America's prisons with nonviolent drug offenders, ruined millions of lives and undermined the Bill of Rights -- especially the Fourth Amendment's protections against unreasonable searches and seizures.
Beyond America's borders, the results have been even worse. The greatest tragedy has occurred in Mexico. When President Felipe Calderón took office in December 2006, he launched (with Washington's encouragement and financial support) a military-led offensive against his country's powerful drug cartels. The result was an explosion of violence that has now claimed more than 50,000 lives. Yet the cartels are more powerful than ever and challenge the Mexican government's control in several parts of the country, especially along the border with the United States.
Mexico's cartels have also set up shop in several Central American countries, putting that region back on Washington's security radar for the first time since the end of the Cold War. Evidence indicates that those criminal syndicates now control vast swaths of territory in Honduras and Guatemala -- perhaps as much as 40 percent of the latter country. Drug violence and intimidation is also beginning to spill over Mexico's border with the United States. Ranchers in southern Arizona, New Mexico, and Texas report increasing encounters with heavily armed cartel enforcers, and some ranch workers openly express fear about working on lands anywhere near the border.
The reason the Mexican cartels exercise such worrisome clout is because they have vast financial resources at their disposal. By most estimates they control at least $35 billion a year of a $300 billion a year industry. Because drugs are illegal, the cartels enjoy a huge black-market premium. As much as 90 percent of the retail price of illegal drugs is a result of that illegality.
Albert Einstein defined insanity as doing the same thing over and over and expecting different results. After waging a futile war on drugs for more than four decades, while causing horrific unintended consequences both here and abroad, it is well past time to try a different approach. The core of a new strategy should be to de-fund the Mexican drug cartels. The only way to do that is to eliminate the lucrative black-market premium. And that means abandoning the failed prohibition model. Prohibition didn't work against alcohol in the 1920s, and it's not working any better today against marijuana and other illegal drugs.
The saddest part of the silence about the drug war in the presidential campaign is that foreign leaders and the American people seem ready for a serious debate about the issue. Numerous foreign leaders, including two former presidents of Mexico, Ernesto Zedillo and Vicente Fox, and former president Fernando Henrique Cardoso of Brazil, have denounced the war on drugs. And their ranks continue to grow, as other countries grow weary and frustrated at Washington's demands that they accomplish the impossible and shut off the flow of drugs into the United States.
Domestically, change is in the wind as well. A 2011 Gallup survey showed that 50 percent of Americans were in favor of legalizing marijuana -- by far the largest percentage since the surveys began in the 1970s. Furthermore, solid majorities (some 57 percent) of both Democrats and Independents endorsed legalization. Indeed, the only demographic sector in the survey that firmly embraced prohibition consisted of people over 65. The mortality tables alone indicate that sentiment in favor of legalization is likely to prevail within the next decade or so.
In short, a presidential candidate who is bold enough to advocate a reassessment of the war on drugs is likely to score both diplomatic points abroad and political points at home. Challenging the conventional wisdom would, of course, require political courage. But that is supposedly a quality we seek in a president. Governor Romney and President Obama have a prime opportunity to demonstrate that they possess that quality.
Ted Galen Carpenter, a senior fellow at the Cato Institute, is the author of nine books on international issues, including 'The Fire Next Door: Mexico's Drug Violence and the Danger to America' (forthcoming, October 2012).
This post is part of the HuffPost Shadow Conventions 2012, a series spotlighting three issues that are not being discussed at the national GOP and Democratic conventions: The Drug War, Poverty in America, and Money in Politics.
HuffPost Live will be taking a comprehensive look at America's failed war on drugs August 28th and September 4th from 12-4 pm ET and 6-10 pm ET. Click here to check it out -- and join the conversation.