ALT Parental alienation is not a contested theoretical construct—it is a functional strategy of psychological abuse that inflicts profound, lifelong trauma and imposes measurable economic costs on the Irish state. The 17 alienating behaviours are clinically recognised, internationally documented, and increasingly codified in comparable jurisdictions. Codifying these behaviours into Irish law—following the lead of Denmark, Scotland, and Brazil—is a vital component of Ireland's national duty to protect children, achieve its suicide prevention goals, and exercise fiscal responsibility. By bridging the gap between clinical reality and legal enforcement, Ireland can move toward a family justice system that truly prioritises child welfare, long-term mental health, and economic resilience. The cost of inaction is not abstract. It is measured in children's lost relationships, adult mental illness, courtroom resources, and billions in preventable state expenditure. The cost of action is a modest