Strategic alliances are vital for organizations seeking competitive advantage, access to new markets, and opportunities to share resources. However, forming such alliances entails considerable risks, particularly in the area of partner selection. This study integrates insights from existing literature with empirical evidence from Iranian small and medium-sized enterprises (SMEs) in the aerospace sector to identify key criteria influencing partner selection and their evolving importance after alliance formation. The findings highlight that technological capability, financial health, and prior experience are critical factors in the initial stages of partner selection, while aspects such as managerial compatibility and cultural alignment gain significance as alliances progress. The research underscores the dynamic nature of strategic partnerships and emphasizes the necessity of continuous evaluation to ensure long-term effectiveness. By addressing the interplay between trust and risk and exploring the complexities of interrelated variables, the study contributes to the refinement of risk management frameworks. The results provide both theoretical insights and practical guidance for organizations aiming to improve their strategic decision-making in forming and sustaining successful alliances.