This paper examines the notion that derailment potential and leadership strength are complex but related to facets of leadership development and effectiveness. Using data from 766 managers from two subsidiaries in Japan and US, the authors argue that managers can develop leadership strength to guard against some aspects of derailment. Further, the paper shows that aspects of culture have a buffer effect on relationships of leadership strength and derailment. The relationship between leadership strength and derailment was found to be stronger in US than in Japan. Implications of the findings are discussed for talent management practices and cross-cultural studies.