Unable to compel a modern-day “currency alignment” between gold and silver on China, in 1839 the British navy launched an assault against China to coerce the resumption of the India to China opium trade into the port of Canton. The British East India Company maintained a monopoly in opium, which was the only significant product exported to China. China maintained a large trade surplus with the British; and when the Chinese Emperor took steps to restrict trade — opium had long been illegal in China and England, but enforcement was non-existent — the war was on.
An observer commented in the Bombay Telegraph, “As an article of commerce, opium stands out without a parallel. From the skilful management and cultivation of about 100,000 acres of land, the East India Company produces an article which sold at a profit of several hundred per cent, yields to them a net revenue, annually of nearly three millions sterling.” Under the Treaty of Nanking, Britain succeeded in forcing opium upon China’s population. The Concert of Europe’s nonaggressive policy practiced within the Continent didn’t extend to colonial wars that were carving up whole continents elsewhere.