Infants, toddlers, and preschool‐aged children have unique developmental needs that render them vulnerable to challenges associated with parental military service. We used a sample of military‐connected families with 3–6‐year‐old children (N = 104) to examine associations among children’s socioemotional development and fathers’ trauma‐related deployment experiences, including perceived threat during deployment and exposure to combat and the aftermath of battle. Of these potential stressors, only paternal perceived threat during deployment was significantly associated with measures of mother‐reported child adjustment. Fathers’ perceived threat during deployment was associated with child behavior problems even after accounting for demographic variables and current paternal symptoms of posttraumatic stress, depression, and anxiety, β = .36, p = .007. The association between fathers’ perceived threat during deployment and child behavior problems was mediated by several family processes related to emotion socialization, including father‐reported sensitive parenting, indirect effect (IE) B = 0.106, 95% CI [0.009, 0.236]; parent–child dysfunctional interaction, IE B = 0.119, 95% CI [0.014, 0.252]; and mother‐reported family emotional responsiveness, IE B = 0.119, 95% CI [0.011, 0.258]. Implications for future research on the intergenerational transmission of traumatic stress as well as prevention and intervention efforts for military‐connected families with young children are discussed.