“Not much of a gambler,” Chuck Rosenberg says about himself, a tad sheepishly. Indeed, in the seven deadly sins department, the new chief of the Drug Enforcement Administration is something of a zero: He’s never smoked marijuana, doesn’t drink alcohol, and lists as his only vice an excessive intake of Diet Dr. Pepper.

Such abstemiousness may be a prized attribute in the head of the lead agency in the War on Drugs, which kicked off with the founding of DEA, under a measure signed by President Nixon, in July 1973. From his office headquarters in Northern Virginia, Rosenberg oversees nearly 5,000 federal agents in 220 U.S. cities and nearly 90 other locales around the world. These are some of America’s toughest and bravest uniformed – and undercover – officers, men and women who risk their lives to take down the most ruthless and heavily-armed narco-trafficking cartels.

The irony for the mild-mannered, bespectacled Rosenberg, a career federal prosecutor and former FBI official, is that someone so averse to gambling now spends his days grappling with the very thing gamblers court most assiduously. “We incur a lot of risk in our operations: legal risk, personal risk, all sorts of risk,” the DEA chief said at his agency’s headquarters. “And managing that risk in a smart way – figuring out where we ought to be and what we ought to be doing, prioritizing our work without stepping on the creativity and the passion of the men and women in the field – that’s a challenge.”

Foremost on Rosenberg’s agenda – the issue that every one of his 21 special agents in charge, fanned out across the country, cite as the number one problem in their respective jurisdictions – is the surge in heroin use in the United States over the past few years. The Centers for Disease Control reports that heroin usage or dependency surged by nearly 150 percent between 2007 and 2013, and that casualty rates from the drug nearly doubled in the last two years of that span.

“It’s back, and it’s back with a vengeance,” Rosenberg told Fox News in his first TV interview since taking the reins of the agency in May. “There's an enormous supply of heroin; it's cheap. In fact, it's a lot cheaper than prescription pills. If you take oxycodone and hydrocodone for a football injury and you get hooked, you're going to pay a dollar a milligram on the street for a pill – thirty milligrams, thirty dollars, give or take. Heroin is probably one-fifth the price, and because it has a similar chemical effect, a similar pharmacological reaction, folks make that transition.”

Asked if he sees substance abuse as a national security threat, Rosenberg at first demurred, seeking the reporter’s definition of a threat to national security. Encouraged to employ his own, Rosenberg replied: “Potentially. This is a multi-billion dollar industry. What are the bad guys doing with the money that Americans are paying for drugs? What's it funding overseas? I'm sure some of it's going to terrorist organizations; we've seen that. And so that worries me quite a bit.”

U.S. officials note that drug overdoses claim the lives of approximately 44,000 Americans each year – more than firearms or car accidents – and that half of those deaths are attributable to prescription pills. Asked if legal or illegal drugs pose the greater threat, Rosenberg said “both dimensions” are creating major problems for law enforcement and society in general. The acting administrator would not say outright that legal drugs are over-prescribed, but he hinted at his harboring such views, saying: “I’m not a doctor but I do know this … We’re about 5 percent of the world’s population. We use about 95 percent of the world’s hydrocodone. So draw your own conclusion.”

The recent decriminalization of marijuana usage in selected jurisdictions across the United States – Colorado and Washington state, most notably – has created a conflict between local law enforcement, sworn to uphold local laws, and federal law enforcement officers, for whom the federal statutes outlawing marijuana remain very much in effect. “I’ve been very clear to my special agents in charge: If you have a big marijuana case, if that in your jurisdiction is one of your biggest problems, then bring it,” Rosenberg said.

With new ballot measures on marijuana cropping up in almost every election cycle, and decriminalization appearing to be gaining broader support, Fox News asked Rosenberg about the continued inclusion of the drug in the federal government’s harshest category of narcotics:

ROSEN: Two of the last three presidents of the United States have acknowledged having used marijuana. Bill Clinton famously said that he didn't inhale. Barack Obama has written fairly extensively about his marijuana use, has been photographed with marijuana; and others have explicated on that subject even further. Isn't that itself – the fact that here we have two men who used marijuana, in varying degrees, and who then went on to become president of the United States – a kind of a prima facie argument that it is time to remove marijuana from Schedule I of the Controlled Substances Act?

ROSENBERG: Yeah, I don't think so.

ROSEN: Why not?

ROSENBERG: Marijuana is dangerous. It certainly is not as dangerous as other Schedule I controlled substances; it's not as dangerous as heroin, clearly, but it's still dangerous. It's not good for you. I wouldn't want my children smoking it. I wouldn't recommend that anyone do it. So I don't frankly see a reason to remove it. We, by the way, support, and have supported, a lot of legitimate research on marijuana, fully behind that; I think it's great. If we come up with a medical use for it, that would be wonderful. But we haven't.

When the questioning took a slightly different tack, he stood firm:

ROSEN: I’ve never seen two guys get thrown out of a bar because they started fist-fighting after smoking a joint. All right? But we’ve seen [that] every Friday and every Saturday night brings just such occasions as a result of the legal distribution of alcohol. Isn’t there some common-sense disparity, or irony, or disconnect in that?

ROSENBERG: Probably, yeah. Right? So I don’t know that you’re arguing that they’re both good; you may be arguing that they’re both bad. As I said earlier, marijuana is less dangerous – clearly less dangerous – than heroin. It’s easy to draw that line. But I’m not willing to say that it’s good for you, or that it ought to be legalized. I think it’s bad for you and that it ought to remain illegal.

ROSEN: From that answer, one might infer that you think alcohol should also be illegal.

ROSENBERG: No, I’m not going to say that. We – we tangled with that as a society in the 1930s. And we know how that went. That’s the law of the land; I get it. I choose not to drink alcohol but I’m not going to impose that on anyone else.

Since Mexico is a primary point of origin for illegal drugs consumed in the United States, including heroin, our neighbor to the south exercises an outsized claim on the attention of the DEA administrator. The brazen escape from a Mexican prison in July of the Sinaloa cartel druglord Joaquín Archivaldo Guzmán, also known as “El Chapo” – one of the world’s most ruthless and dangerous criminal kingpins, now at large – underscored the challenges for U.S. law enforcement in collaborating with a nation-state where official corruption is so widespread. “Not that I can share with you,” Rosenberg answered when pressed on whether U.S. authorities have any better idea of El Guapo’s location today than the day after his escape.

Asked if there is a single sector of the Mexican state apparatus that is free of corruption, Rosenberg answered: “I don't know. I would hope so.” Later, he cited the Mexican agents who work with DEA task forces and called them “good and trusted allies,” their very existence evidence that “pockets” of integrity in the Mexican system exist.

With his cautious demeanor, Rosenberg shrewdly steers away from any question that smacks, or even faintly reeks, of controversy. Though he is perhaps in a better position than any other U.S. official to corroborate or refute the charge, he will not comment on Donald Trump’s recent assertion that the Mexican government is deliberately sending rapists and gang members across the U.S. border. Nor will Rosenberg say whether a “spiritual deficit” is partly to blame for the skyrocketing rates of heroin dependency. And he will not answer questions about his role in an epic controversy of the Bush-Cheney era: when an internal clash over reauthorization of a surveillance program critical to the War on Terror, in March 2004, nearly triggered mass resignations at the Department of Justice.

“Happy to talk about the Washington Nationals and their diminishing chances of making the playoffs this year,” he’ll say instead, with a sly smile.

Controversy, it turns out, is not one of the risks the DEA chief is willing to manage.

James Rosen joined Fox News Channel (FNC) in 1999. He currently serves as the chief Washington correspondent and hosts the online show "The Foxhole." His latest book is "Cheney One on One: A Candid Conversation with America's Most Controversial Statesman" (Regnery, November 2, 2015).