Alliances are complex projects with high uncertainties in risks. Trust is still an issue between the Alliancing Leadership Team (ALT) and Alliancing Management Team relationship (AMT) despite the pain share and gain share commercial arrangement. Although the concept and components of trust have been defined and discussed by various researchers, the volatility of trust under different situations has not been tested and is clearly a gap within the research domain. Based on semi-structured interviews with the members of the ALT and AMT of an alliance project in Victoria the underlying trust based relationships between the AMT and ALT was investigated using the Soft Systems Methodology (SSM). Results demonstrate that cognitive, affect, system and cognitive-affect based trust are mediated by common good, needs, sharing, breach temptation and mishap situations. This is determined by the perception of risk sharing based on the performance of Target Output Cost (TOC) in a pain share mode. Trust can only facilitated in an alliance when TOC has reached its gain share expectations but in an event of cost overrun distrust erodes trust completely. This research demonstrates that the adversarial culture of the Australian construction industry cannot be changed by the implementation of trust principles alone. The culture of suspicion dominating the ideological view of the construction industry requires organizational learning between alliance parties to execute appropriate behaviors, aligned with the alliancing philosophy, to effectively achieve ideal collaboration.