Another sustaining factor is the obligatory roles placed on wives and what they come to understand as their "duty". For example, "Vietnamese women are expected to sacrifice for their families, especially for their children, which includes, for some, acceding to husbands’ sexual demands" (Kwiatkowski, 2016). Their "duty" is to maintain family harmony and happiness (Kwiatkowski, 2016). In Guatemala, violence within marriage is so normalized that wives come to believe that this is ‘the way things are’ and it is simply their role as a wife to endure the violence (Menjívar, 2016). This "…normalization of violence…rests on a continuum of coercive power that makes possible the mistreatment of women not only in their homes but also in the community, neighborhood, and society at large" (Menjívar, 2016). Further, because many of these women believe giving sex is their duty, they do not characterize their experience as marital rape (Bergen, 2016). However, "…women who have experienced forced sex in marriage understand this experience as an abuse or violation", they just may not characterize it as marital rape (Torres, 2016). Violence is so entrenched in many cultures it simply becomes a way of life, and wives are left to believe they must learn to endure it (Menjívar, 2016).