The future complexity of strategic issues in international structural change was demonstrated by UK and SA ports. This arose from the likely extent of structural constraints and the effects of stakeholder power. From a review of emerging Advanced Systems Theory a new Boundary -spanning perspective of strategy was developed, that led to the specification of conceptual circumstances of potential outcomes of change. Since existing systems methodologies could not accommodate future power relationships, a new methodology and data collection technique was developed. The circumstances were developed into multiple scenarios which were judged by international decision-makers. These judgements were subjected to quantitative and qualitative analysis from a Strategic Choice Perspective. The outcome was a Boundary -spanning 'Long-term Strategic Service Industry' model which proposed the outlines of the future strategy and organisational structure that ought to be adopted to meet 'public interest' constraints. A dual subject and methodological contribution was made.