Aim: This paper uses Conservation of Resources Theory (CORT) to examine how leadership behaviours impact the personal resources (discretionary power, Psychological Capital and wellbeing) and outcomes of police officers delivering policing services. CORT explains employee motivation in response to work and is used to explain employee responses when working under stressful conditions. Methods: Structural Equation Modelling and multi group comparisons of survey data from Italian and English police officers. Results: Over three-quarters of Italian police officers’ wellbeing can be explained by the variance of leadership, PsyCap and discretionary power. In contrast, two thirds of the English police officers’ wellbeing is predominantly explained by their PsyCap. Furthermore, wellbeing explains much of the Italian and English police officer’s level of engagement. The comparative means for authentic leadership, wellbeing and engagement were both relatively low. Implications: CORT explains that poorly supported police officers cannot protect society and maintain law and order when their wellbeing is compromised, hence the present leadership behaviours compromise the sustainability of societal wellbeing.