Energy trade periodically aligns Northern importing -consuming countries against predominantly Southern producing -exporting countries. Conflict appears to follow a cyclical pattern, whereby Northern firms invest in developing Third World hydrocarbon resources to meet consumer demand until market conditions enable unilateral efforts by host sovereigns to augment fiscal take and ownership share and to impose output restrictions, thereby elevating prices and revenues. Although markets eventually correct themselves, major consuming-country governments, to the extent that seller's markets attributable to exporter actions harm short-term consumer welfare and alternative options for restoring buyer's markets are lacking, have varying incentives to support military intervention. Shifting market conditions and power balances suggest six ideal-typical energy trade conflict strategies. Finally, to the extent that exporting states succeed in converting higher hydrocarbon revenues into energy-intensive economic growth, co-operative phases within this conflict pattern could yield to increasingly zero-sum interconsumer rivalry.Energy trade and foreign direct investment (FDI) are again pitting 'Northern' consumer and corporate interests against sovereign producers in the global 'South'.1 As the history of the oil sector indicates, multinational firms extracted Southern energy reserves to supply Northern consumption requirements until market conditions enabled Third World producingexporting countries to enlarge sovereign shares of asset values and gain control over extraction. Sustained price hikes then brought demand down, while bringing undeveloped geographical and geological frontiers into play, which multiplied exporters and strained collective output discipline, already attenuated by exporters' proclivity to raise output to serve expanding non-oil fiscal budgets. Recent upsurges in consumption and assertions of sovereign control over FDI suggest that a political -economic 'market cycle' is recurring.Paul A Williams is in the