Economic strategy in Europe, intended to cripple Britain’s economy. It was based upon the Berlin (1806) and Milan (1807) decrees of Napoleon, which declared Britain to be in a state of blockade and forbade either neutral countries or French allies to trade with it or its colonies. At Tilsit (1807) Russia agreed to the system and in 1808 Spain was obliged to join it. Britain responded by issuing Orders in Council that blockaded the ports of France and its allies and allowed them to trade with each other and neutral countries only if they did so via Britain. The restrictions contributed to the War of 1812 with the USA over the right of neutral ships to trade with Europe. It gradually resulted in Napoleon losing support at home and being challenged abroad. His unsuccessful invasion of Russia in 1812 was provoked by Russian refusal to continue the system and it marked the beginning of his downfall.