In a key scene in Clint Eastwood’s fact-based film American Sniper, Navy SEAL Chris Kyle—the deadliest sniper in American military history, with 160 confirmed kills—is attending a barbecue with his family in suburban Texas between one of his four tours of duty. As he sits on the porch with a beer, he is anything but at home; though his surroundings are idyllic, he is still absorbed by the heightened state of awareness that kept him alive in Iraq. Chris’s wife Taya does all she can to maintain normalcy while watching her pressure cooker of a partner out of the side of her eye, fearful of what might activate his as-yet-undiagnosed PTSD. He finally snaps, nearly killing a tame dog before coming back into reality.

“That’s how it is for a lot of Navy SEALs,” says actress Sienna Miller, who portrays Taya in her struggle to counterbalance the boiling intensity of her husband Chris (Bradley Cooper). “[Kyle’s] blood pressure was really high when he wasn’t in combat. When he was in combat, his blood pressure would drop. They actually put him in a simulator and tested it. And if there was gunfire and explosions and he was active, then he was completely level.”

Eastwood’s most intimately insightful film in years is making headlines for Cooper’s transformation into the controversial Kyle and its depiction of his torn sense of duty to his comrades in the field and loyalty to his family back home, the people for whom he’s fighting in the first place. In some ways, the Kyles’ story is extraordinary for Chris’s achievements in combat; in others, it’s the story of every military family. To capture the reality of this difficult dynamic, Miller made a careful study of Taya that reflects her commitment to her clan despite its uncertain future. “[Taya] packs a punch,” says Miller. “She can match him. She’s a toughie. That was something which I noticed about her. At the same time, she’s incredibly vulnerable and incredibly loving and incredibly resilient.”

The Iraq War was launched over a decade ago but Hollywood is only beginning to find its footing in depicting the conflict and its repercussions. American Sniper is determined to orient future films toward the reality of war, both at home and abroad.

Says Miller: “We’ve been at war for a lot of my life … To see a film [like American Sniper] that doesn’t hold back in showing what war is like and the effect that it has on families is really important. I have a huge empathy for not only the people in service who deserve enormous respect and gratitude, but also the people left behind who are sacrificing their lives and their partners’ for the benefit of all of us … Both sides of the coin have to be appreciated. Hopefully, this film will make people think in that way, and also be comforting to people who have been in combat and have come back and feel lost, to a certain degree. I think there will be something in this film that will be comforting to them as well.”

AMERICAN SNIPER | RATED R | IN THEATERS FRI 1.16