This paper examines war widowhood in South Sudan as a gendered social risk that exposes the limits of informal safety nets and strengthens the case for statutory social protection. Since independence, recurrent armed conflict, displacement, market disruption, weak service delivery and patriarchal customary institutions have combined to deepen the vulnerability of women whose husbands have been killed, disappeared, separated by conflict or rendered unable to provide household support. The analysis argues that war widows are often pushed into a paradoxical position: they become primary carers, informal workers, debt managers, guardians of children and custodians of family survival, yet they remain weakly recognised by formal policy systems. The paper uses a conceptual policy-analysis design, drawing on social risk management, feminist political economy, care ethics and rights-based social protection literature to interpret how informal support through kinship, churches, savings groups, neighbours and humanitarian relief cushions immediate distress but rarely provides predictable, adequate or enforceable protection. It develops a Gendered Vulnerability Index and a statutory protection architecture designed around cash transfers, legal aid, child-sensitive benefits, psychosocial support, grievance systems and community-based registration. The paper concludes that South Sudan requires a gender-responsive statutory protection floor that treats widowhood caused by war not as private misfortune but as a public consequence of conflict and state fragility. Statutory social protection should therefore be designed as a peacebuilding, poverty reduction and gender justice instrument rather than a marginal welfare intervention.