Political Power in International Trade

Economic power in international trade is the capacity of one country to impose loss on another by withdrawing from a trading relationship. This paper measures it. A model of the short run represents each trade restriction as a pattern of barred entries in the world matrix of input shares and maps it into a vector of losses by country and sector. The asymmetry between the two countries' losses under the same severance is the measure of power: a gap in substitution, since a buyer's dependence turns on how easily it finds another source and a seller's on how easily it finds another market. When a relationship is barred, buyers lean on alternative suppliers and barred suppliers on alternative buyers already present in the benchmark network, under the ceiling that no producer exceeds its pre-shock scale. The reallocation is a RAS balancing of the disrupted matrix that lets \emph{both sides} adjust together. Across 9,480 counterfactual severances on the 2022 world input--output network, mutual trade dependence is anything but mutual. The average bilateral asymmetry is 0.6 on a scale that runs from balance at zero to complete lopsidedness at one. The United States holds the favorable side in all its relationships, China in all but one. The same tilt runs far down the hierarchy: a severance with Russia would cost Belarus more than a tenth of its economic activity, but Russia only half of one percent. The asymmetry bears only a weak relation to bilateral trade imbalance but closely tracks whether a country sits at the core or the periphery. Power is a property of network position, not deficits.