In recent years, supply chain disruption for critical components in key industries has become an increasingly prominent issue. This paper investigates how to employ inventory strategies to address the disruption risk of critical components under competition. In a supply chain model consisting of one supplier and two competing manufacturers, a two-period game is considered, where in the second period, due to different supply disruption reasons, one or both manufacturers experience supply disruptions. Consequently, manufacturers have an incentive to strategically stockpile inventory in the first period. The analysis reveals that the optimal inventory strategies highly depend on the disruption risks faced by both the focal manufacturer and its competitor. As the disruption risks increase, the optimal wholesale price of critical components and the expected profits of all firms exhibit non-monotonic changes. Interestingly, the disruption risk faced by only one manufacturer may enhance the supplier’s expected profit. Thus, the supplier might deliberately create the disruption risk for a single manufacturer. Accordingly, it is necessary for our government to respond by making a credible threat of sanctions against such suppliers to improve supply security.