Story by Peter O'Dowd

Note: This is part one of a five-part series airing this week, courtesy of the Fronteras Project

The violence that’s roiling Mexico can at least be partly blamed on our own citizens. Even top levels of the federal government now say it’s our demand for pot and cocaine that has sparked deadly turf battles at the border.

That raises the question — just how much do Americans love to get high?

Let’s start with numbers: 22 million. That’s how many Americans use illegal drugs regularly, according to the Department of Health and Human Services. It’s nine percent of the population over age 12 — equivalent to every man, woman and child in Australia.

A significant number end up at drug screening centers throughout the Southwest. Last year, thousands of users and former users came through TASC in Phoenix.

Every day, TASC’s Israel Cano watches a line of users pee into a plastic bottle. First left, then right, he moves his eyes to ensure the samples aren’t tampered with. TASC works with Arizona’s criminal justice system to keep tabs on probation and parole violations. Its lab tests several million samples a year. The people here are America’s typical users. Most are men. Marijuana is the drug of choice.

Barbara Zugor has worked here since 1977. She occasionally gets philosophical about her job.

–Why in 2009, for instance, did almost 17 million Americans smoke pot habitually?

–Why did 7 million abuse prescription drugs?

–Why did a million and a half regularly take cocaine?

–Why is America a country of illicit drug consumers?

“Now, that’s the 64 billion dollar question. And we’re all trying to figure out why is that?” Zugor said. “And until we do, there will probably be drugs and drug abuse in this country.”

PHOTO: Courtesy U.S. Dep't. of Health and Human Services
A snapshot of drug use in the U.S.

Even drug dealers think about these questions.

A former dealer, who agreed to speak on condition of anonymity, said there is no such thing as a casual drug user.

“There’s a ripple effect to everything. Everyone who smokes weed is like a crack addict,” the dealer said. “That’s their fix. That’s their drug. And they’re going to call your phone.”

The demand for the former dealer’s product was constant. Before getting busted in Phoenix, he bought up to five pounds of Mexican pot at a time, and made about $2,000 a week selling it. He claimed to have sold to students. To firemen. Even to military police.

“There were people in their mid-30s, mid-40s on up,” the dealer said.

Gil Kerlikowski is the US Drug Czar. He says it is possible to reduce consumption. Take cocaine, for example. Its use has fallen the past several years. The government isn’t sure why. It could be the US $360 million spent to help Mexico fight its drug war since 2008.

PHOTO: Courtesy U.S. Dep't. of Health and Human Services
A snaphot of the percentage of adults who use illegal drugs broken down by age.

The government believes the entire illicit drug trade in this country brings between $18 and $39 billion annually to Mexican drug cartels. For pot, it’s $60 an ounce. A pound sells for about $425. And that’s for commercial-grade in Phoenix, which is typically cheaper and weaker than domestic marijuana. Pot smokers call Mexican weed Bobby Brown. It’s packed into bricks and shipped through tunnels, or on trucks and on airplanes from Mexico.

“Mexicans are getting a bad wrap. Yeah, a lot of the stuff is coming across the border, but it’s our demand that is bringing it here,” the dealer said. “If you stop the demand, you stop the flow.”

Even the Obama Administration agrees.

“Mexico wouldn’t have quite the level of problems, and a lot of other countries wouldn’t either if we could reduce our own demand,” Kerlikowski said.

But if that were the case, there should be less pot getting across as well. But pot use is steady in this country. According to government reports, it’s supplied by an undiminished flow from Mexico and augmented by the cartel’s new domestic production.

“The overall story is that the price of pot per hour of intoxication is definitely going down,” said Jonathan Caulkins, who studies the drug trade at Carnegie Mellon University.

PHOTO: Courtesy U.S. Dep't. of Health and Human Services
A breakdown of drug users based on race/ethnicity.

Regardless of cost, the majority of pot and cocaine still comes through Mexico. And do users here ever wonder if they’re playing a role in this violent drug war?

“That’s a really good question,” said Tommy Thompson, a Phoenix police sergeant. “I think by the time a person is addicted to drugs, they don’t care where they came from, or what are the consequences to bring the drugs to their table.”

Our former drug dealer agrees on this point. He says his clients were so eager to get high that even the ones who openly worried about feeding the cartel’s bottom line – and it wasn’t uncommon – always ended up forking over another 60 bucks for an ounce of Mexican weed.

“It bothered me to the core, but I did it anyway because the money was good and it had been an identity thing for so long,” the dealer said.

And so he sold more. His clients bought more. And in January, he got caught.

Now every week, a man at the drug-screening center in Phoenix watches him pee into a plastic cup.