"Go to war. See war. Then you can comment on it," says Cain, who is still close to Kyle's widow, Taya
“I tend to react the way I would react if someone were in the room with me,” the former Superman tells PEOPLE Now about his Tweets slamming Michael Moore and Seth Rogen for their seemingly critical comments about snipers and the Oscar-nominated movie.
“Had he said what he said in the room with me, my exact response would have been what I said: ‘Seth, I like your movies, but right now I want to kick your ass,'” he added.
Continues Cain, who visited troops in Iraq in 2005, where he says he “saw awful, terrible things”: “The guy’s a hero. Go to war. See war. Then you can comment on it.”
Cain, 48, says his Tweets sparked a discussion with his teenage son Christopher, who was in the room when he was responding.
“It might create a little bit of a firestorm,” he says he told his son. “I could have worded it better, but it demonstrated how I felt I’m unapologetic about it. How could I apologize for defending our men and women in uniform? How could I apologize about defending Chris Kyle? There’s no way. The guy’s a hero.”
The former Lois and Clark star became tight with Kyle when they were paired in 2012 to perform military-style operations on the NBC competition show Stars Earn Stripes, and he says he is still close to Kyle’s widow, Taya, who is featured in this week’s cover of PEOPLE.
“Chris’s mission became helping other servicemen and women transition back into real life,” Cain tells PEOPLE Now while wearing a cap sporting the logo of the Chris Kyle Frog Foundation. “He would take guys out shooting that’s how he lost his life that what his foundation’s mission is now.”
Kyle died in 2013 at age 38 at a Texas gun range. Eddie Ray Routh allegedly shot and killed Kyle after the father-of-two brought Routh to the range to help him cope with his PTSD.
The trial for Routh, who is charged with murder, begins Feb. 11.
“I’m in touch with Taya all the time,” says Cain. “Anything she needs, or the kids needs, there are a lot of people willing to come to their aid, and I’d be fortunate to count myself as one of them.”
For more on Taya and Chris Kyle, pick up the latest issue of PEOPLE, on newsstands Friday