This study examined private security deployments in critical national infrastructure (CNI) and the protection of foreign assets in Uganda, analyzing the governance frameworks, operational performance, and strategic risks associated with the increasing reliance on licensed private security organisations (PSOs) to provide protective security for Uganda's oil and gas infrastructure, telecommunications networks, banking systems, strategic government facilities, diplomatic missions, and multinational corporate assets. As Uganda's Albertine Rift oil and gas sector approached first commercial production with attendant international investment and infrastructure development, and as the proliferation of foreign direct investment across telecommunications, banking, construction, and agribusiness sectors dramatically expanded the footprint of foreign-owned assets requiring protective security, the strategic, governance, and legal dimensions of private security CNI deployments had assumed unprecedented national security importance. Drawing on a cross-sectional study of 196 respondents comprising CNI security managers, PSO operations directors, Uganda Revenue Authority and Bank of Uganda asset protection officials, foreign diplomatic mission security coordinators, Internal Security Organisation (ISO) liaison officials, and UPDF liaison officers at CNI sites, supplemented by structured CNI site security assessment protocols and analysis of PSO contract documentation, the study employed descriptive statistics, Pearson correlation, multiple linear regression, and Structural Equation Modelling to examine how CNI-specific PSO vetting and clearance standards, CNI security protocol compliance, and intelligence sharing and state coordination mechanisms influenced CNI security effectiveness outcomes including threat detection capability, incident response performance, and protective security resilience ratings. Descriptive statistics revealed significant gaps in CNI-specific security governance (means 2.94–3.47). All three governance dimensions were significantly correlated with CNI security effectiveness (r = 0.583–0.748, p < .001). The three dimensions collectively explained 65.2% of variance in CNI security effectiveness (R² = 0.652, F = 41.87, p < .001). SEM confirmed intelligence sharing and state coordination as the strongest total effect predictor (total β = 0.521), with CNI protocol compliance partially mediating this relationship. Recommendations address CNI security tiering legislation, intelligence coordination protocols, foreign asset security governance frameworks, and national CNI protection strategies.