The film -- which chronicles an unhappily married woman's obsession with historical couple King Edward VIII and American divorcee Wallis Simpson -- is the first major work the 53-year-old has released since she and Ritchie split.
The singer told the magazine it wasn't a mere coincidence that she started writing the screenplay for "W.E.," which deals with the hardships and regrets of marriage, 10 years into her own relationship.
"I was certainly asking a kind of existential question that I think people ask when they've been married that long: what is the perfect love?" she explained to Newsweek. "Because when you start off, everything's great and lovely, and the person you've married is flawless, and you're flawless."
But as time passed, the singer said she began to notice "cracks in the veneer" of her marriage. She told Newsweek that the gradual realization made her ask herself, "'How much am I willing to sacrifice?'"
It's not the first time the singer has spoken out about her failed union. In August 2009, Madonna told Rolling Stone that she was thankful to have been able to concentrate on her work during her "challenging" marriage. Otherwise, she told the magazine, she "may have thrown [herself] off a building."
Madonna and Ritchie share custody of their two sons, Rocco, 11, and six-year-old David Banda, whom the couple adopted from Malawi. Madonna also has two other children, 15-year-old Lourdes and five-year-old adopted daughter Mercy James. She will be performing at this Sunday's Superbowl.
HuffPost Lifestyle is a daily newsletter that will make you happier and healthier — one email at a time. Learn more