The early history of Netflix is a story of inevitable hits and surprise successes. The inevitable hits included Kevin Spacey and David Fincher’s House Of Cards. The first big surprise as Netflix rolled out its streaming service across the world was unquestionably Narcos.

This breathless and gripping tale of drug traffickers in Latin America and the US agents sent to take them down – or at least contain them – arrived with negligible fanfare in 2015. It had no stars. Half the dialogue was in subtitled Spanish. And we knew how the story finished – with Wagner Moura’s Pablo Escobar gunned down by Colombian special forces on a roof in Medellín in 1993 at age 44. Nothing about it screamed blockbuster.

And yet, out of the gate, it was a smash. Part of that had to do with Moura’s searing Escobar. It was a performance that contained multitudes. But it also owed something to the subject matter. The war on drugs may seem a rather hackneyed topic in 2020. Narcos, though, surprised us by using the subject as a prism through which to interrogate human nature itself.

Escobar was a monster, but also a vain, needy man who wanted to be loved. Beyond the guns and the cocaine, this was a story of an individual setting himself against the world. You could disapprove of his actions while empathising with him to an extent.

With Escobar fated to meet a sticky end, there was, however, a time limit on Moura’s involvement. What’s been remarkable is that Narcos has continued and now returns for the second season of Narcos: Mexico. It has transitioned from Colombia to the current battleground of the drugs wars – the Mexico of El Chapo and the Tijuana Cartel and tens of thousands of “disappeared”.

“Our greatest accomplishment was getting our audience to stick with us after Wagner Moura,” says show runner Eric Newman. “My real celebration came afters season three [the first after the death of Escobar]. We proved we had command of this universe.”

The star of Narcos: Mexico is Diego Luna. He plays Miguel Ángel Félix Gallardo, who headed the notorious Guadalajara cartel through the ’70s and ’80s. Gallardo was a very different creature from Escobar. And Luna’s performance is nothing like Moura’s, though he is just as hypnotic in his way.

“Pablo Escobar was a very emotional force. Diego Luna’s character is more cerebral. What Escobar wanted was to be loved. What Gallardo wanted was to be a key cog in the machine. They’re all different. The Cali Cartel guys [the subject of Narcos season three] wanted to be overlooked, to be ignored.

The first season of Narcos: Mexico told the true story of American Drug Enforcement Administration agent Kiki Camarena (Michael Peña) who was tortured and murdered by the Guadalajara cartel (including a young El Chapo). Series two picks up the story as the DEA takes the war to Gallardo and his goons, with Scoot McNairy’s DEA agent Walter Breslin heading the charge.

One difference between the original Columbia-set Narcos and Narcos: Mexico is that in Colombia the Escobar years are now part of history. The country has its problems. But it has essentially left the drugs wars behind. In Mexico, they rage on.

“They appreciate that we’re honest about who is at fault on both sides,” says Newman of attitudes in Mexico towards the Netflix series and the negative light it arguably casts on Mexican society (the police are portrayed as by turns brutal and corrupt). “There will be people who are sick of it. Mexico is in a different place than Colombia in their drug wars. They are still in it, with no sign of it slowing. Whereas in Colombia they have kind of out-run their past. In Mexico, they are still in the tragedy.”

Hot Press tells Newman that Ireland has had its share of violent gang conflicts recently and that a Narcos: Ireland would not be implausible. He agrees, while, perhaps inevitably, seeing crime here through the lens of the Troubles and terrorism.

“I’m fascinated by criminal enterprise,” he says. “It always has a reason to exist. It’s more than, ‘I’m just a bad guy’. There’s a great movie about the IRA called Odd Man Out [from 1947]. James Mason plays an IRA gunman who is wounded. Through the whole movie he gets passed from person to person…Crime is sometimes the last refuge of the victim, particularly one who was the victim of societal oppression.”

Still, Latin America is different in one respect, he says. “They make it. The coca leaf grows only in the Andean region of South America. And they share this giant border of 1,900 miles with the largest market for drugs in the world: that is the United States.”

Narcos has not been universally praised. One recurring contention is that it glamorises thugs such as Escobar and Gallardo. “It’s always been a quick and easy criticism,” says Newman. “It gets thrown around and I always have the same response – which is that what is often mistaken for glamorising is humanising. We feel an obligation as storytellers to make them human beings.

“You can say ‘oh these are monsters’. Well, anyone in the right circumstances is capable of being a monster. What I love about Diego’s performance is that he has that contemplative quality: you see the weariness. Heavy is the head that wears the crown. And you really feel that with him.”

• Season two of Narcos: Mexico is on Netflix