When you think of the US Drug Enforcement Administration (DEA), you might conjure images of pudgy hardass types like Breaking Bad's Hank Schrader smashing down the doors of New Mexico's meth labs. Or, after this week, of the very troubling revelation that agents stationed in Colombia allegedly attended "sex parties," paid for by drug cartels, over a period of years.

Much less well-known are the agency's undercover missions, conducted across the world, from Thailand to Canada, West Africa and Northern Europe — often without host governments even knowing about it. Since drugs consumed in America come from all over the world, goes the reasoning, clandestine operations staged in hostile corners of the globe can theoretically stop the goods even entering the US.

Such stings cast light on a massive global trade, which links coke traffickers with arms smugglers, terrorists, corrupt militaries, and crooked politicians, and is driven in part by rampant drug use across Europe — where cocaine consumption more than doubled in the 2000s.

One of the most stunning of these DEA busts took place less than two years ago off the coast of Guinea Bissau, a small West African nation known for extreme corruption and nearly total lawlessness. DEA agents, posing as members of the Colombian guerrilla group FARC, tricked José Américo Bubo Na Tchuto, the former head of Guinea Bissau's navy, into a huge phony drug deal that landed him in a Brooklyn prison 4,000 miles away.

When VICE filmed with Special Agent Lou Milione for its HBO segment "Lines in the Sand," he told us about the notorious sting.

"We portrayed ourselves as drug traffickers," he said. "There was a real FARC member at the earliest part, who was interested in linking up with a real Guinea Bissau leader, and we were fortunate to be able to infiltrate ourselves, then present ourselves as the FARC."

The DEA team, which had been alerted to alleged planeloads of cocaine flying from Venezuela into the hands of Na Tchuto and his military, tricked the navy boss into coming aboard a "chic" 115-foot luxury yacht produced by the DEA. He'd been lured by the promise of an long term relationship with the fake FARC, and an offer of $1 million per ton of coke coming through Guinea Bissau under his protection.

The DEA pounced, arresting Na Tchuto, and began a long journey to the friendly island nation of Cape Verde in the central Atlantic Ocean, some 2,500 miles away.

"We didn't realize at the time that flat bottomed boats are probably not great for that kind of distance," he said. "The boat was basically destroyed when we got back." Na Tchuto was charged under US law for drug trafficking, and put on a plane to New York.

When coke hits West Africa from Latin America, like in this instance, it's normally bound for Europe. And that means a long, arduous journey across the continent, right through the Sahara desert — regions of which are under the control of Islamist groups including al Qaeda in the Islamic Maghreb (AQIM).

In one operation, in December 2009, the DEA again posed as members of the FARC to try and catch these so-called narco-traffickers.

"We had undercover negotiations in Ghana with Malian traffickers associated with AQIM that were part of that plot to kidnap Westerners. But we sucked them into our conspiracy to try to reveal what was going on, and also get them charged... They believed we were going to move between 500 and 1000 kilos all the way up into Spain," Agent Milione told VICE.

"They were charging us 3000 a kilo to bring it up there," he said. "So, their pure revenue on that — just on that, would have been one-and-a-half to three million dollars."

Exclusive video, captured by the DEA in West Africa that they claim proves the first ever link between Latin American cartels and al Qaeda-linked groups, can be seen in the VICE on HBO segment "Lines in the Sand."

Cocaine's Desert Trail

After filming in Venezuela for "Lines in the Sand," where VICE saw some $10 million worth of cocaine apparently bound for West Africa, we headed to Agadez, in Niger, a small town on the southern edge of the Sahara desert, hoping to pick up the trail of cocaine headed north to Europe. An ancient hub of smuggling of all kinds, the region has been invigorated by the modern drug trade.

Brand new Toyotas, tricked out for the long journey through chaotic southern Libya, line the streets or Agadez. GPS units and satellite phones are on sale on every corner. Toubou tribesmen have stories of bandits holding drug convoys ransom for hundreds of thousands of dollars. One trafficker VICE spoke to told us about large 10-car convoys leaving the town at dusk to collect huge caches of drugs in the desert.

Islamist groups come incredibly close to the town. A recent music festival was disrupted by a "well-armed convoy, circulating without headlights," according to organizers.

The DEA says that these groups "tax" cocaine as it passed through the region, using the proceeds to fund their jihad. According to a British government report, AQIM and others don't find this apparent contradiction particularly troubling: "theology...does not explicitly warn against selling [drugs] to support Islam," the report claims. To Islamists: "proximity to drugs trafficking can be justified as a way of supporting a 'good' Islamic lifestyle," just as "slavers historically accommodated their faith with their trade."

Despite the DEA's enthusiastic assertions, no one has ever found hard evidence of cocaine in Niger. But as part of VICE's investigation there, we met a respected investigative journalist, who passed us the below video of what he says is about 800 grams of cocaine — worth about $50,000 in the pubs and clubs or Europe — held in police custody there.

As far as we know, this is the first ever hard evidence of cocaine passing through Agadez, or the region as a whole. It was seized by police from a Nigerian trafficker (or possibly victim of human trafficking, forced to carry drugs as payment for her transit to Europe). Since the drugs' journey north would almost certainly pass through regions where "protection" is offered by Islamist groups, the DEA's belief that drugs fund jihad appears to be well-founded.

What's more, since the government of Niger has reported seizing hilariously small amounts of cocaine — in 2006 it claimed to have seized 56 grams — it is highly likely that the cocaine would simply have been sold or re-entered circulation at some point.

While Europe's bankers and wankers show no sign of stopping putting coke up their noses, it seems likely few will know the lengths taken to get the stuff to their toilet stall. Most cocaine still arrives in London and Madrid by plane — one trafficker we met in Venezuela claimed up to 100 people aboard each Lufthansa flight out of Caracas have condoms stuffed with coke in their digestive systems — but a large amount still travels by sea and road though the badlands of Africa, enriching arms dealers, terrorist and politicians along the way.

Watch VICE on HBO's "Lines in the Sand" to find out more.

Follow Alex Chitty on Twitter: @AlexChitty