Love or hate Liam Neeson’s late-career rebirth as an action star, the person to hold responsible for the Irishman’s string of grizzled, gun-toting badass roles is Pierre Morel, director of Taken. That unexpected 2008 hit, which turned a $25 million budget into $224 million at box offices worldwide, showed producers that the then-50-something actor could snap bones with the best of them and that moviegoers enjoy finely aged beef. In Morel’s latest flick, The Gunman, the 50-year-old Frenchman is introducing 54-year-old Sean Penn, who’s done plenty of drama and comedy but no full-on action, as an equally hard man capable of summoning the Reaper in myriad ways.

Loosely based on Jean-Patrick Manchette’s 1981 novel The Prone Gunman, the flick follows ex-military contractor and assassin Jim Terrier (Penn), who becomes a target and must figure out who wants him dead and why. There’s a lost-love story and a physical and mental toll from a violent and traumatic career—because, let’s be real, a two-time Oscar winner isn’t signing up for the latest xXx—but Penn is most eye-opening in his chiseled physique and the movie’s impressive action set pieces. Score another K.O. for the old guys.

Complex recently spoke to Morel to investigate the appeal of old men busting guns, what makes action scenes good, and how Penn got ridiculously ripped for the role.

Liam Neeson in Taken and now Sean Penn in The Gunman. What appeals to you about the aging action hero?
I must be stupid. I never actually think about it that way. It’s all about telling stories and characters that I like. And the characters I describe in those two movies cannot be young rookies. So, they have to have a little bit of time under their belt and develop some experience and have a backstory, which is deep and long, and that’s why they become compelling to tell. So, it’s not about the aging action hero, it’s about interesting multiple-layered characters that carry more than action but emotion, I guess.

If Neeson’s career post-Taken is any indication, audiences do seem to enjoy a grizzled old guy beating up young punks, though. Why do you think that is?
I wish I knew. If I knew I’d have the recipe to make hits every time. What would be interesting to know, which I’ve never tried to figure out yet is, why does it appeal to all generations and not only to people of the same age? ’Cause that’s been the case. OK, if I’m a 50-year-old man, here I am, happy to see a guy my age doing things that I cannot do. But it also appeals to females, to younger generations, and so I guess it’s not about the age. It’s about the emotional connection you can have with the characters. And yeah, Liam had a great ride after Taken because he keeps on playing characters with emotion and not just action heroes. Everything he has done, there’s always an emotional journey, an emotional arc in the movie. That’s what it’s all about. Whether you repeat that and the audience wants to see it again is something that is out of my control, but that’s why we’re going to see Liam’s movies again and again.

[sean penn] was as intense in his acting parts as he was in the action parts.

What is most important to you in action sequences?
That they are coherent with the story and not just for the sake of violence. I always try to make them impressive and efficient, but without overly, graphically glorifying violence. It needs to be embedded in the story. If it’s just for action’s sake, there’s something missing. If the action pieces that you have in the movie are a logical outcome of the plot, then it’s fun. If the way they’re set and choreographed are both coherent with the character and make sense, then that’s what I’m interested in.

There are action directors whose goal seems to be simply to one-up themselves, either with the size of the explosions, the kinds of martial arts practiced, the number of combatants, the setting, etc. Is that weak action filmmaking?
No, it’s just a different pleasure. It’s just both components of the same pleasure. But don’t get me wrong: When I go to movies, I’m a moviegoer and a movie lover, I like going to see action movies. I have that different pleasure seeing over-the-top action because it’s pure entertainment. It’s just fun. It doesn’t apply to movies I’ve done so far because the story is what drives the movie and not the action part of the movie. So, yeah. Coherency.

The Gunman is Sean’s first “action movie.” What was your experience working with him on the action elements?
The great thing with Sean is that he’s a hardworking actor. Once he takes on a character, he becomes that guy 100 percent. I’ve said that often, but it’s both on the drama part and also on the physical part. He was as intense in his acting parts as he was in the action parts. And the training was hard, and his investment was extremely helpful. It’s helpful to have an actor of that level that can give you so much. And also, once again, because his character has all those conflicts and issues, physical and mental, it was interesting to build up his action pieces around that a little bit, to use his potential issues and flaws or weaknesses, to put them into the choreography so it works.

Sean brings a tremendous amount of complexity to the character, but one of the things that stands out is just how ripped he was for this role, which makes sense with him playing an ex-military contractor. What sort of training did you put him through?
I couldn’t tell you specifically, ’cause I was not there when he was training. He was doing his training, whatever he was doing, but I was prepping the movie the whole time. I was not there to attend him lifting iron. But I’m sure it was intense. It wasn’t just working out to be in shape and look cool, because he always has [been in shape and looked cool]—good bones, he’s got already. Although he never used it in movies, he’s got physicality. But the training, rehearsing the choreography and making the choreography, is already demanding, so it keeps you in shape.

Was there much military training for him?
Yeah. He also went to intensive training with guns and how to hold them and how to behave with a gun, because it’s shocking when people portray characters that are supposed to have been living all their lives around guns and be comfortable with guns in their hands and they actually don’t even know how to hold them. Sean trained for every part he needed to train for to be a believable ex-military man.

You’ve said The Gunman is not a political statement but that having the political element makes it more than just action for action’s sake. How did you decide upon the post-colonial African elements of the movie and the updates from the book?
It’s just a backdrop in the book. It just starts there, but it’s not part of the plot itself. We wanted to make it part of the plot because it made sense to give him a more complex background and to link whatever is done in Africa, in his early days, with what is going on later on and why they’re after him. We picked one specific country [the Democratic Republic of Congo], we could have picked any other neighboring countries, because there are similar situations in central Africa: the Congo, Rwanda, Liberia, Sierra Leone, you name it. It’s often linked with resources being extracted and exploited and because there’s often corruption in these countries. It leads to extremes of behaviors.

In the back of your mind, do you hope that in entertaining people they might actually learn something or investigate geopolitical issues?
If it’s an eye-opener, great. It’s not the purpose of the movie, but it was the same for all my movies actually. The first one we shoot, B13, was a small French movie, but the backdrop and the plot was about the ghetto housing plans in the outskirts of Paris. And Taken was about human trafficking. From Paris with Love was about terrorism. And this one is about African situations. So, I always like to set the realistic backdrop to the stories and use it as a part of the plot. To me, it’s more attractive because you can relate to real things. If doesn’t mean I don’t like sci-fi or total fantasy, but in this particular case I felt a need to ground them in real life.

Did you use many consultants or rely on your own research?
We put it in a period and with global situations that are accurate, but the events are not. There never was such an assassination in Africa. There’s been many more, I’m sure, but not this one, so it was fictional in a real world. So we didn’t have specific advisors for that but we did have ex-military guys, ex-personnel, ex-contractors, that actually have been working in Africa a lot. And they did bring us a lot of the reality needed for these situations.