As was doing research for the fifth book in my mystery series featuring Homicide Detective John Santana, I came across some interesting facts, which reinforced my believe that drugs have as much chance of being legalized as I do of becoming president. But my skepticism is based on something quite different than you might think.

Whenever those opposed to legalizing drugs are asked to defend their position, they often cite health concerns and moral, spiritual, and political reasons for their opposition. In some instances they’ll cite economic concerns, arguing that when compared to the social costs of drug abuse and addiction, government spending on drug control is minimal.

But there’s one economic argument for keeping drugs illegal that is rarely mentioned, and it has to do with the billions of dollars that are laundered through the global banking system every year.

The United Nations Office on Drugs and Crime estimates the amount of money laundered globally in one year to be 2 – 5% of global GDP, or $800 billion – $2 trillion US dollars. Senator Carl Levin estimates that “$500 billion to $1 trillion of international criminal proceeds are moved internationally and deposited into bank accounts annually.” Estimates place the dirty money flowing into U.S. coffers during the 1990s amounted at $3-$5.5 trillion.

According to a report prepared by James Petras, Professor of Sociology at Binghamton University, the dirty money flowing through the major U.S. banks far exceeds the net revenues of all the IT companies in the U.S. The yearly inflows also surpass all the net transfers by the major U.S. oil producers, military industries and airplane manufacturers.

The bottom line is that “without dirty money the U.S. economy would be totally unsustainable, living standards would plummet, the dollar would weaken, the available investment and loan capital would shrink and Washington would not be able to sustain its global empire.”

And here’s the bad news. Petras believes the amount and importance of laundered money is increasing.

Conservative economist Milton Friedman once said that, “if you look at the drug war from a purely economic point of view, the role of the government is to protect the drug cartel,”––and, I would add, by extension the banks that illegally launder their drug money.

So the next time someone asks you why we can’t legalize drugs forget the traditional arguments and tell them the truth. The world and U.S. economy and banking systems are dependent on keeping drugs illegal.