Repercussions of war captivity may transmit to spouses of former prisoners of war (POW) via posttraumatic stress symptoms (PTSS). Overidentification with their partners underlies the PTSS experienced by former wives of POWs, thus implying impaired self-differentiation. Although wives’ indirect exposure to their husbands' captivity and subsequent PTSS has been associated with the wives' PTSS and differentiation, the combined effects remain unclear. Furthermore, previous cross-sectional studies could not illuminate directionality. This prospective study investigates (a) the moderating role of indirect exposure to captivity in the association between husbands’ PTSS and wives’ PTSS and differentiation; and (b) the directionality of the association between wives' differentiation and PTSS over time. The wives of both former POWs (n = 143) and combatants (n = 102) were assessed 30 (T1) and 38 (T2) years after the 1973 Yom Kippur War. The wives of former POWs endorsed higher PTSS and fusion differentiation, η2 p =.06 to.14. Indirect exposure to captivity moderated the associations between husbands' PTSS and wives' PTSS, Cohen's f2 =.01 to.03. The association between the wives' differentiation and PTSS over time was bidirectional, β = −0.18 to 0.68; R2 =.54 to.73. Results suggest a vicious cycle between PTSS and differentiation, and the need for clinical interventions that further differentiation for spouses of prolonged trauma victims.