A Mining company contemplating a major investment in a developing country will always make a careful assessment of the non-commercial risks. The possibility that the government might, at some time in the future, expropriate the investment, and the uncertainty surrounding the whole topic of compensation for expropriated assets, are matters which would normally have to be taken into account. However, no less important in practice, particularly where there are detailed stipulations relating to the fiscal regime, is the risk that the government might in the future seek to extinguish or modify its contractual obligations by an exercise of legislative competence.